.223 Wylde chamber, Comparison
The major dimensional difference between the chambers that fire the .223 Remington and the 5.56 x 45 NATO is the longer and larger-diameter "freebore" in the 5.56 chamber (0.0566" vs 0.0250" length, 0.2265 vs 0.2240 diameter). Freebore is a short and smooth section of the barrel that is located after the case mouth, but located before the start of the rifling "grooves and lands". The standard Wylde-spec chamber uses an even longer freebore length of 0.0619, to allow longer bullets (and thus heavier) to be assembled at the absolute maximum "Cartridge Over All Length" (COAL). Be aware that the freebore of a chamber can be special-ordered in a variety of lengths.


.223 Wylde chamber, Comparison
The larger diameter of the 5.56 freebore allows for continued functioning when experiencing minor fouling of gunpowder residue build-up, which is essential for the rapid firing of high volumes of ammunition in combat.


.223 Wylde chamber, Comparison
The .223 Remington cartridge is currently manufactured to be used as a single-shot in a bolt-action rifle, so the .223 chamber benefits from a slightly tighter dimension in several places, compared to the 5.56 NATO. The slightly "looser fit" in the military 5.56 chamber increases operational reliability during rapid cartridge insertion and extraction. This is of special interest when taking into consideration any minor manufacturing variances in the ammunition, and also minor case dents acquired during transportation during combat. This cycling reliability is of intense concern when using the 5.56 NATO cartridge in a light machine gun, such as the M249, as well as the general-purpose M4 combat rifle.


.223 Wylde chamber, Comparison
However, the larger-diameter 5.56 freebore can occasionally have a minor detrimental effect on accuracy on any given random shot, when using the standard combat 62gr M855 cartridge. The .223 Wylde-spec chamber uses the slightly looser 5.56 NATO chamber dimensions around the case for cycling reliability in a semi-auto firearm, along with the tighter freebore of the .223 Remington for a more consistent accuracy.


.223 Wylde chamber, Comparison
It has been commonly stated that a 5.56 chamber can fire a .223 cartridge without concern, but firing a 5.56 cartridge in a .223 chamber is ill-advised. To further clarify, a given .223 Remington-chambered rifle may be able to safely handle the elevated chamber pressures of a 5.56 NATO cartridge, but they are not required to be manufactured to do so. All ".223 Wylde" marked barrels are required to meet the higher pressure standard.


.224 Boz
The .224 Boz cartridge was developed in the late 1990s with the purpose of defeating body armour.


.224 Boz, Design
The .224 Boz began as a 10mm Auto case necked down to .223. Original trials were successful, with this round firing a 50 gr projectile chronographed at over 2,500 ft/s (760 m/s).


.224 Valkyrie
The .224 Valkyrie (5.6×41 mm) cartridge is a .22 caliber (5.6 mm) rimless bottlenecked intermediate rifle cartridge, developed by Federal Premium Ammunition to rival the performance of the .22 Nosler, while still being compatible with modern sporting rifles.


.224 Weatherby Magnum
The .224 Weatherby fMagnum (5.56×49mmB) is a sporting cartridge that was developed in 1963 by Roy Weatherby after about 10 years of development. It is a proprietary cartridge with no major firearms manufacturers chambering rifles for it other than Weatherby. It was originally called the .224 Weatherby Varmintmaster when it was introduced alongside the Weatherby Varmintmaster rifle, but the rifle was discontinued in 1994 and the cartridge was renamed.


.224 Weatherby Magnum, Design
The cartridge design began years earlier but its introduction was delayed, at least in part, because of the unavailability of a suitable action. An earlier high-velocity .22 caliber round from Weatherby called the .220 Weatherby Rocket was based on the .220 Swift though it was unsuccessful and never manufactured.


.224 Weatherby Magnum, Performance
Performance is similar to the popular .22-250 and the lesser used .225 Winchester putting it in between the .220 Swift and .223 Remington cartridges. Possibly because of the similar performance and popularity of the .22-250, this round has never gotten a very large following. Costs for ammunition and rifles for this round also tend to be much more expensive.


.224 Weatherby Magnum, Sporting use
.22 caliber rifles are legal in some areas for big game up to the size of deer or larger. Convention holds the .224 Weatherby and similar cartridges are better suited to long-range varminting. Similar statements are made concerning other "big" 22 caliber cartridges like the .220 Swift and .223 WSSM.


.224 Weatherby Magnum, Sporting use
Currently many states in the United States do allow 22 caliber rifles on big game, but the majority require a minimum of 6mm. Well known firearms author P.O. Ackley believed that fast 22 caliber cartridges were suitable for medium-large game. Craig Boddington has said that such cartridges are suitable for smaller deer. Bullets suited for hunting big-game are available from major manufacturers such as Nosler and Barnes.


.224-32 FA
The .224-32 FA is a proprietary cartridge designed in 2009 by Freedom Arms, Inc. for use in their Model 97 revolver. The .224-32 FA was designed to provide a high-performance .22 caliber centerfire cartridge that would work in a revolver, and is capable of taking varmints and predators up to the size of coyotes.


.224-32 FA, Firearms chambered for .224-32 FA
As of 2011, there is only one factory chambered firearm in .224-32 FA, the Freedom Arms Model 97 revolver. It has a six shot cylinder, adjustable rear sights, and barrel lengths available in 4.25 in (10.8 cm), 5.5 in (14 cm), 7.5 in (19 cm), 10 in (25 cm).


.225 Winchester
The .225 Winchester cartridge was introduced in 1964 by the Winchester Repeating Arms Company.


.225 Winchester, Description
Based on the .219 Zipper case but with a reduced rim diameter to fit the common .473" bolt face, it was intended as a replacement for the .220 Swift cartridge which had a reputation for burning out barrels. Despite having a modern straight taper design, the round was eclipsed by the older .22-250 Remington, already a popular wildcat introduced commercially a year later.


.225 Winchester, Description
The .225 Winchester was chambered in factory rifles by Winchester (Models 70 and 670) and Savage (Model 340). All commercially produced rifles chambered in .225 Winchester were turn-bolt or break actions. Winchester ceased producing rifles chambered in .225 Winchester in 1971, however seasonal production of loaded ammunition and brass continues by Winchester. Reloading dies for the round are readily available.


.225 Winchester, Description
The .225 Winchester's case is a parent case for some of SSK Industries' popular line of JDJ cartridges designed by J.D. Jones, chosen for its strength and semi-rimmed design which makes it well suited for use in break-open actions.


.240 Apex
The .240 Magnum Rimless Holland & Holland (also known as the .240 Apex and the .240 Super Express) and the .240 Magnum Flanged are a pair of centrefire sporting rifle cartridges developed in English gunmakers Holland & Holland in the 1920s, primarily for use in hunting deer and plains game.


.240 Apex, Overview
The ballistic performance of the .240 H&H in factory loads is very similar to that of the .243 Winchester, with a 100-grain (6.5 g) bullet with a diameter of .245 inches (contrary to the .240 name) giving a muzzle velocity of approximately 2,900 feet per second (880 m/s). When it is loaded at the same pressure as the .243 WSSM using modern powders, the .240 H&H has the potential for slightly better performance.


.240 Apex, Overview
Most bolt-action rifles made for the .240 H&H will be amply strong enough to handle handloaded cartridges at high pressure.


.240 Weatherby Magnum
The .240 Weatherby Magnum was developed in 1968 by Roy Weatherby. In the development of his own .240in/6 mm cartridge, Weatherby was significantly influenced by both the success and the limitations of the .244 H&H Magnum cartridge devised in England by his friend and colleague David Lloyd. It was the last cartridge to be designed by Roy Weatherby.


.240 Weatherby Magnum, Design
The .240 Weatherby Mag. is a proprietary cartridge used only in Weatherby rifles. This particular Weatherby case is unique: other than shape, it isn't physically based on other Weatherby cases, having the same rim diameter and a similar length to the .30-06. It utilizes the traditional Weatherby rounded double shoulder and a belted case with a length of 2.496in, significantly shorter than the 2.8in case of the .244 H&H Mag.


.240 Weatherby Magnum, Performance
In terms of velocity, the .240 Weatherby Magnum was once the fastest commercially produced 6 mm cartridge. There were several faster wildcat rounds available, but the .240 Wby. Mag. outclassed the 6 mm Remington and the newer .243 WSSM by about 150 ft/s (46 m/s). However, the lightweight .243 WSSM 55gr Ballistic Silvertip now outpaces Weatherby's offerings according to some. Loading data from Western Powders puts the .240 Wby. Mag. at over 4,000 ft/s (1,200 m/s) with a 62 grain Barnes bullet.


.240 Weatherby Magnum, Performance
While favoured by some varmint hunters, the .240 Wby. Mag. is not much liked by some reloaders because the case cannot be formed out of any other brass; one either has to buy Weatherby ammunition or reload used Weatherby cases which tend to be more expensive than those for more common cartridges. With heavier bullets the .240 Wby. Mag. makes for a good deer hunting cartridge, but it does tend to require a long (>23 inches (580 mm).) barrel in order to achieve peak performance.


.242 Rimless Nitro Express
The .242 Rimless Nitro Express, also known as the .242 Vickers and initially called the .242 Manton, was a rimless bottleneck centerfire rifle cartridge developed by Kynoch for J. Manton & Co of Calcutta and introduced in 1923.


.242 Rimless Nitro Express
The .242 Rimless is very similar to the .243 Winchester in performance, although the cartridge is significantly longer. It fired a 100 gr projectile at 2800 fps.


.243 Winchester
The .243 Winchester (6.2×52mm) is a popular sporting rifle cartridge. Developed as a versatile short action cartridge to hunt both medium game and small game alike, it "took whitetail hunting by storm" when introduced in 1955, and remains one of the most popular whitetail deer cartridges. It is also commonly used for harvesting blacktail deer, pronghorns and mule deer with heavier rounds, and is equally suited to varmint hunting with lighter rounds. The .243 is based on a necked down .308 Winchester, introduced only three years earlier. Expanding monolithic copper bullets of approximately 80 to 85 grains or traditional lead rounds of 90 to 105 grains with controlled expansion designs are best suited for hunting medium game, while lighter rounds are intended for varmints.


.243 Winchester
In at least ten U.S. states and the United Kingdom, the .243 or similar cartridges are the smallest bore cartridges that are legal for hunting deer; this has been revised in the UK to allow Muntjac and Chinese Water Deer to be taken with .22 (5.56mm) chambered weapons. The cartridge can be extremely accurate to 300 yards (270 m) and beyond, but may not retain enough terminal energy to reliably drop medium game at that distance. Highly experienced hunters use the .243


.243 Winchester
Winchester to routinely drop bucks up to 250 pounds (110 kg), while less experienced hunters can be just as capable with the .243 because of its very low recoil yet high velocity. Besides hunting applications, the cartridge is popular with target and metallic silhouette shooters for those same recoil and velocity properties, with superb accuracy.


.243 Winchester
The .243 Winchester has regularly made the top five of rankings for "Best Whitetail Deer Hunting Cartridges" from sources such as Field and Stream and Outdoor Life, and its widespread popularity (called the "whitetail hunter's favorite" by the Browning Arms Company and "American favorite" by American Rifleman) assures chamberings in newly manufactured offerings of not only bolt-action rifles, but also semiautomatic rifles (e.g., Browning BAR), lever action rifles (e.g., Henry Long Ranger), and pump action rifles (e.g., Remington 7600). Gun Digest estimates that (as of the end of 2018) the .243


.243 Winchester
Winchester is the second-most popular of all hunting rifle chamberings (after the long action .30-06). Commentators such as popular ammunition author Chuck Hawks have opined that the .243 Winchester (as a "6mm NATO" round) should replace the 5.56×45mm NATO (.223 Remington) for most United States Armed Forces use cases but the .243 has, as of 2021, never been used as a military cartridge.


.243 Winchester, History
Well-regarded Field and Stream editor and Harvard-educated technical gun enthusiast Warren Page began experimenting with wildcatting a .243 caliber (6.2mm) round in the 1940s sometime after the 6mm Lee Navy was discontinued. When the .308 Winchester was introduced in 1952, Page started necking down the .308 design into a new .243 wildcat cartridge. After Page's hunting success with and much writing about this new version, Winchester developed a factory loaded .243 soon thereafter. It was first introduced in 1955 for the Winchester Model 70 bolt-action and Model 88 lever-action sporting rifles and quickly gained popularity among sportsmen worldwide.


.243 Winchester, History
It was a ground-breaking development with at first only two factory loads, combining a versatile and effective combination of 80-grain bullets optimized for high-velocity, long-range performance for varmint hunters (e.g., groundhogs, coyotes, prairie dogs) and 100-grain bullets suitable for game up to the size of deer and pronghorn antelope. Its predecessor in the Winchester lineup, the very similar .257 Roberts, could have easily been selected to accomplish the same tasks, but was not available factory loaded with either lighter, varmint-weight bullets or pointed, long range spitzer (pointed) bullets, so it never achieved the popularity of the newer round.


.243 Winchester, History
Remington also saw the 6 mm (.243 in) family as suitable for this dual-purpose use and introduced their version, the .244 Remington, in the same year (1955) based upon the .257 Roberts necked down to accept .243 bullets up to 90 grains in weight. The Winchester round remains available today whereas the .244 Remington, later renamed the 6mm Remington with the introduction of 100-grain bullets, is far less popular even though it can push all bullet weights slightly faster with maximum loads due to the larger capacity case. The fact that the .243 Win was originally offered in a 1 in 10 inch rifling twist rate, a rate better able to stabilize heavier, 100- and 105-grain bullets, versus the .244 Remington's 1 in 12 inch twist (hence the 90-grain factory offering) was also a factor in their popularity.


.243 Winchester, History
Since the enactment of the Deer Act 1963 in the United Kingdom, which stipulates a minimum bullet diameter of .240 inches, together with minimum levels of muzzle velocity and bullet energy, the .243 has long been perceived as the entry-level caliber for legal deer-stalking. Firearms that would normally be chambered in .308 Winchester/7.62×51mm NATO are sometimes available in .243 in countries–such as Spain–whose regulations restrict or forbid private ownership of so-called military calibers (restricted to bolt action-repeating rifles). No military is known to currently designate this round for service.


.243 Winchester, History
In a non-sporting context, bolt-action rifles chambered for the .243 were utilized by the Los Angeles Police Department's special weapons and tactics (SWAT) unit during its early years. A specialist 115-grain projectile can move up to 3,150 fps from a 28-inch barrel, or over 3,000 fps from a 26-inch barrel.


.243 Winchester, History
P. O. Ackley created an improved version of this cartridge called the .243 Winchester Improved (Ackley). Like other improved cartridges, this created a steeper shoulder and blew the sides out, giving about 10% more powder capacity, and some small improvement in velocity.


.243 Winchester, Performance
With very little recoil, even less than that of the .30-30 Winchester cartridge introduced sixty years earlier, the .243 brings higher chamber pressures, larger powder volumes, and sharply tipped bullets, which combine to lend the .243 more muzzle energy and far greater downrange energy than the .30-30 is able to achieve. The .243 Winchester has also been found to shoot flatter and more accurately than the 7mm-08 Remington out to 500 yards, with less recoil yet also less terminal energy.


.243 Winchester, Performance
The recoil has been measured to be so light that it "can be shot by anyone that can handle a rifle." Among popular small-bore rifle ammunition the .243 does have approximately three times the recoil factor of the .223 Remington and twice the recoil factor of the .22-250 Remington, but only half the recoil factor of the more powerful long action .25-06 Remington (without muzzle brakes). As the .223 and .22-250 are not recommended for deer hunting, the .243 has the lowest recoil factor among small bore deer hunting cartridges.


.243 Winchester, Performance
Lack of overpenetration on medium game has traditionally been perceived either as a problem (lack of exit wounds and blood trails) or as a feature ("uses up all the energy in the deer") of traditional lead .243 cartridges versus larger and heavier rounds, but monolithic copper .243 ammunition weighing as little as 80 grains (5.2 g) negates this characteristic and causes adequate penetration and blood trails through even larger-bodied medium game like wild hogs.


.243 Winchester, Performance
The .243 produces a velocity of 3,200 feet (980 m) per second from factory-loaded expanding monolithic copper projectiles weighing 85 grains (5.5 g) fired from a 24-inch (610 mm) barrel. Other variations of commercially loaded .243 ammunition are available with bullet weights ranging from 55 grains (3.6 g) up to 115 grains (6.8 g). Twist rate of the barrel can sometimes be a factor in deciding which bullets to use, 1:10 being the most popular as it is sufficient to stabilize up to 100 gr bullets. However, for very low drag-profile or bullets heavier than 100 gr, a 1:8 or 1:7 (for 115 gr VLD bullets) is necessary.


.243 Winchester Super Short Magnum
The 243 Winchester Super Short Magnum or 243 WSSM is a rifle cartridge introduced in 2003. It uses a .300 WSM (Winchester Short Magnum) case shortened and necked down to accept a .243in/6mm diameter bullet, and is a high velocity round based on ballistics design philosophies that are intended to produce a high level of efficiency. The correct name for the cartridge, as listed by the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI), is 243 WSSM, without a decimal point. Winchester has discontinued the manufacture of 243 WSSM ammunition. As of the first half of 2016, Winchester/Olin did manufactured and release for sale some WSSM ammunition. The product is only manufactured periodically, often on inconsistent intervals.


.243 Winchester Super Short Magnum, Design
The 243 WSSM is an addition to the Winchester Super Short Magnum (WSSM) family of cartridges, which also include the .223 WSSM and the .25 WSSM, and the idea behind the 243 WSSM was to develop a compact, higher velocity version of the well-established and internationally popular .243 Winchester unveiled by Winchester in 1955. The 243 WSSM was first introduced in 2003.


.243 Winchester Super Short Magnum, Design
The 243 WSSM's case is unusually short and fat in profile, contrasting markedly with most other rifle cartridges, and is intended to take advantage of what ballisticians have shown is the more uniform and efficient burning of propellant powder when it is held in a short, fat stack by the cartridge case.


.243 Winchester Super Short Magnum, Performance
In their ballistics tables, Winchester list a very high muzzle velocity of 4,060 ft/s (1,240 m/s) with a 55-grain (3.6 g) projectile for this cartridge. Based on Hodgdon reloading data typical velocities should range from approximately 4,000 ft/s (1,200 m/s) with a 58-grain (3.8 g) bullet to approximately 3,000 ft/s (910 m/s) with a 100-grain (6.5 g) bullet. The percentage gain in performance over the older .243 Winchester is around 10% or less.


.243 Winchester Super Short Magnum, Performance
This cartridge is usually used for small game such as varminting, and used for animals as large as deer.


.243 Winchester Super Short Magnum, Advantages
Compared to other factory 6mm sporting cartridges the 243 WSSM is capable of functioning in the AR-15. Other factory produced 6mm cartridges like the 243 Win and 6mm Rem are both too long for the AR-15 and require the AR-10 platform.


.243 Winchester Super Short Magnum, Advantages
The 243 WSSM is 3⁄8 in (9.5 mm) shorter than the 243 Win, giving the 243 WSSM the ability to fit in a super-short action rifle. Thus 243 WSSM rifles can be lighter, have stiffer actions and have faster actions to cycle.


.243 Winchester Super Short Magnum, Advantages
The 243 WSSM gives generally a 10% increase in velocity over the 243 Win.


.244 H&H Magnum
The .244 Holland & Holland Magnum cartridge was created in 1955 in Great Britain by deerstalker and rifle-maker David Lloyd of Pipewell Hall, Northamptonshire and Glencassley in Sutherland, Scotland, and is not to be confused with the smaller-cased and much milder 6 mm (.244 in) Remington.


.244 H&H Magnum
Stalking on extremely steep deer forests such as his own at Glencassley, Lloyd was in search of a "canyon rifle" cartridge that would shoot exceptionally fast and with a very flat trajectory across deep valleys and over distances out to 300 yards (270 m) and more, to make range estimation less critical for accurate bullet placement, and to deliver a hard-hitting bullet weighing a minimum of 100 grains. The .244 H&H Magnum easily met these criteria.


.244 H&H Magnum, History
Based upon the well-proven .375 H&H Magnum rimless belted big game cartridge case heavily necked down, the .244 H&H originally fired a 100-grain (6.5 g), aluminum-jacketed, copper-pointed bullet pushed by 74 grains (4.8 g) of non-cordite smokeless (nitrocellulose) powder, and returned a muzzle velocity of about 3,500 feet per second (1,100 m/s). That load and velocity remain standard for the commercially loaded cartridge today; although handloaders can achieve higher velocities with careful load tuning. The .244 seldom performs well in barrels less than 26 inches (660 mm) long, owing to the need for a longer bore to allow pressure and bullet velocity to reach intended levels.


.244 H&H Magnum, History
Lloyd was unable and unwilling to embark upon commercial cartridge production, and consequently "gave" the cartridge to veteran London rifle and ammunition makers Holland & Holland Ltd., who in 1954 had paid him £250 towards his cartridge development costs. H&H quickly adopted it, the cartridge acquired the prestigious "H&H" appellation, and both H&H and David Lloyd went on to build significant numbers of very high quality bolt-action deer-stalking rifles in .244 H&H Magnum calibre (see Lloyd rifle). Initially, commercially loaded ammunition was manufactured by IMI Kynoch at its Birmingham, England factory. Commercially, this cartridge has only ever been loaded with 100-grain (6.5 g) bullets: lighter- and heavier-bulleted loads have been created by handloaders.


.244 H&H Magnum, History
Chuck Hawks, a prominent US commentator on rifle cartridges, opines that, "the .244 H&H Magnum represents some sort of high water mark in the development of the 6 mm cartridge. To use an aviation analogy, you could think of it as the Concorde of rifle cartridges."


.244 H&H Magnum, History
David Lloyd, the .244's originator, went on to develop a still more powerful prototype round by reducing the case body taper and increasing the already large power capacity to produce the "David Lloyd 6 mm Magnum". His hope was to use bullets heavier than the .244 H&H standard 100-grain (6.5 g); but this cartridge was never commercially produced, and only two prototype Lloyd rifles are believed to have been chambered for it.


.244 H&H Magnum, History
In the early 1990s British fieldsports author and ballistician Colin McKelvie had a custom rifle built on a BRNO CZ Magnum action, with a .244in Border Barrel with a 1:7 fast twist. Using handloads with very-low-drag (VLD) .244in hollow-point bullets of 115 grains (7.5 g), accuracy of 0.63 MOA was achieved, with average muzzle velocity of 3,630 ft/s (1,106 m/s) and acceptable chamber pressures. This level of performance is what Lloyd had sought with his "improved" .244 H&H Magnum.


.244 H&H Magnum, Controversy
While the belted .244 H&H Magnum could be considered the velocity/energy pinnacle of 6 mm/.240in cartridges, that power comes at the cost of significant muzzle blast, as well as shorter-than-average barrel life; in addition to which commercially loaded ammunition is expensive. Because of these drawbacks the cartridge never came into widespread popularity, and has never been offered as a chambering by any of the mass-market riflemakers. The .244 H&H rather fell by the wayside in favour of 6 mm rifles in the same general class such as the .240


.244 H&H Magnum, Controversy
Weatherby Magnum (for which it had been an inspiration to designer Roy Weatherby), and also the various 6.5 mm Magnums. The .244 H&H still has its adherents, however, and occasional rifles are still chambered in this caliber by Holland & Holland and others. Ammunition is still made for Holland & Holland and used cases can be handloaded.


.246 Purdey
The .246 Purdey, also known as the .246 Flanged, is an obsolete centerfire rifle cartridge developed by James Purdey & Sons and introduced in 1921.


.246 Purdey, Overview
The .246 Purdey is a rimmed cartridge originally designed for use in Purdey's own double rifles. Never popular or widely used, the cartridge offers slightly less power than the .243 Winchester.


.246 Purdey, Overview
As is common with cartridges designed for double rifles, the .246 Purdey was offered in one loading, firing a 100 gr projectile at 2950 fps.


.25 ACP
The .25 ACP (Automatic Colt Pistol) (6.35×16mmSR) is a semi-rimmed, straight-walled centerfire pistol cartridge introduced by John Browning in 1905 alongside the Fabrique Nationale M1905 pistol.


.25 ACP, Design
The cartridge was designed by John Browning for early blowback pistols that lacked a breech locking mechanism. The cartridge was designed to duplicate the performance of a .22 Long Rifle cartridge, when fired from a two-inch barrel. The .25 caliber was the smallest case Browning could use that still had space for a primer pocket. The greased, coated lead bullet design, standard for the .22 Long Rifle of the day, was replaced with a copper jacketed round nose profile for more reliable feeding in self-loading pistols. The bullet weight was typically 50 grains, keeping with the sectional density of the 40 grain .22 caliber bullet.


.25 ACP, Design
The cartridge is of semi-rimmed design meaning that the rim protrudes slightly beyond the diameter of the base of the cartridge so the cartridge can headspace on the rim. A recessed extractor groove allows an extractor to grab the cartridge reliably. It is one of the smallest centerfire pistol rounds in production, and is commonly used in small, so-called "vest pocket" pistols. The .25 ACP achieved widespread use after Colt introduced the Browning-designed Fabrique 1905 vest pocket (sometimes referred to as 1906) to the United States as the Colt Model 1908 Vest Pocket.


.25 ACP, Design
Though the .25 ACP was designed for semi-automatic pistols, various .25 ACP revolvers were produced in the early twentieth century by Belgian, French, and German gunmakers such as Adolph Frank and Decker. In the late twentieth century, Bowen Classic Arms produced a custom Smith & Wesson revolver in .25 ACP.


.25 ACP, Design
Following World War II, the Italian Lercker machine pistol was chambered for the .25 ACP, but achieved little distribution.


.25 ACP, Performance
The use of the .25 ACP allows for a very compact lightweight gun, but the cartridge is relatively short ranged and low powered, putting it in the same class as the .22 LR rimfire cartridge but at a significantly higher cost. Although the .22 LR is slightly more powerful when fired from longer rifle barrels, the .25 ACP is viewed by some as a better choice for personal defense handguns due to its centerfire-case design, which is inherently more reliable than a rimfire cartridge.


.25 ACP, Performance
Manufacturers have loaded commercial hollow-point bullets to higher velocities than standard 50-grain (3.2 g) full metal jacketed loads. Firearms chambered for the .25 ACP cartridge run the gamut from inexpensive, simply made guns like the Raven MP-25 and Jennings J-25 to higher quality and relatively expensive guns like the Baby Browning, Walther TPH, and Beretta 950 Jetfire. The tiny cartridge has also been used in some precision crafted target pistols.


.25 ACP, Performance
Raven MP-25 .25 ACP Chrome with faux mother of pearl grips and push up safety.


.25 NAA
The .25 NAA was introduced by North American Arms company, for a smaller and lighter Guardian model.


.25 NAA
It is based on a .32 ACP case necked down to accept .251-inch diameter (.25 ACP) bullets.


.25 NAA, History and design
The cartridge was originally conceivedof  and prototyped by gunwriter J.B. Wood, and called the "25/32 JBW".


.25 NAA, History and design
North American Arms and Cor-Bon Ammunition then further developed the cartridge, and the NAA Guardian .25 NAA pistol combination for production in consultation with Ed Sanow.


.25 NAA, Introduction
The finalized cartridge and pistol were introduced at the 2004 SHOT Show.


.25 NAA, Introduction
It followed the successful introduction of two other commercial bottleneck handgun cartridges, the .357 SIG in 1994 (which necked a .40 S&W case down to accept .355 caliber bullets); and the .400 Corbon in 1996 (which necked a .45 ACP case down to accept .40 caliber bullets).


.25 NAA, Performance
According to NAA's website, the .25 NAA's 35 gr bullets travel faster (1,200 f.p.s.) and hit harder (20% more energy on average) than larger, .32 ACP caliber, bullets.


.25 Remington
The .25 Remington (also known as the .25 Remington Auto-Loading) is an American rifle cartridge. A rimless, smokeless powder design, this cartridge was considered to be very accurate by period firearm experts and suitable for game up to deer and black bear.


.25 Remington
The .25 Remington cartridge dates to 1906 and its introduction by Remington in the Model 8 rifle. Other rifles chambered for the .25 Remington include the Remington 14 slide-action, Remington 30 bolt action, Stevens 425 lever-action, and Standard Arms rifles. Due to their similar dimensions, the .25 Remington, .30 Remington, and .32 Remington together were known as the Remington Rimless cartridge series. Firearm manufacturers generally offered all three of these cartridges as chamberings in a rifle model rather than just one of the series. The series was competitive with Winchester Repeating Arms Company's contemporary lever action offerings: .25-35 Winchester, .30-30, and .32 Winchester Special.


.25 Remington
The .25 Remington case was shortened and necked down to .22 caliber to form Lysle Kilbourn's wildcat .22 Kilbourn Magnum Junior and the rimless version of Leslie Lindahl's wildcat .22 Chucker.


.25 Remington
Harvey Donaldson also used the .25 Remington case in early experiments that would eventually lead to the creation of the .219 Donaldson Wasp. Donaldson later switched his experimentation to Winchester .219 Zipper brass after the launch of that cartridge in 1937.


.25 Remington
The .25 Remington was chambered primarily in the Remington model 8 autoloader and Remington model 14 pump action, as well as the short-lived Standard Arms model G and model M rifles.


.25 Remington
Although case capacity of the .25 Remington is slightly greater than the .25-35 Winchester, .23-35 Winchester loading data can be used to work up loads for the .25 Remington.


.25 Short
The .25 Short (also called the .25 Bacon & Bliss) is a .25 in (6.35 mm) American rimfire handgun cartridge.


.25 Short
Introduced for the F. D. Bliss revolver in 1860, it was also available in a number of other inexpensive weapons of the period. It was never offered as a rifle caliber.


.25 Short
With a 43 gr (2.8 g; 0.098 oz) outside lubricated bullet over 5 gr (0.32 g; 0.011 oz) of black powder, it is similar in appearance to the .22 Short. Its power is comparable to the black powder loadings of the .22 Long Rifle. It was available from both Remington and Winchester.


.25 Short
The round continued to be commercially available until 1920, but is now considered a collectible.


.25 Stevens
The .25 Stevens was an American rimfire rifle cartridge. To differentiate from the related .25 Stevens Short it is sometimes also referred to as .25 Stevens Long.


.25 Stevens
Developed by J. Stevens Arms & Tool Company and Peters Cartridge Company, it was developed between 1898 and 1900; catalogs suggest it was introduced in 1898, but most sources agree on 1900. It was offered in the Crack Shot No. 15 rifle, which debuted in 1900. It was also available in the Favorite rifle, which was first released in 1894 and discontinued in 1935. It originally used a 10 to 11 gr (0.65 to 0.71 g) black powder charge under a 67 gr (4.3 g) slug; this was later replaced by Smokeless powder.


.25 Stevens
Some handguns were also chambered for .25 Stevens, most notably the Stevens-Lord single-shot pistols.


.25 Stevens
The round was available with either solid lead or hollow point bullets and developed a good reputation for small game (such as rabbit) and varmints.


.25 Stevens
In comparison to the .22 Long Rifle some sources note that its ballistics suffered from an excessively high trajectory for a rifle cartridge (a drop of 5.1 in (130 mm) at 100 yd (91 m)), while others praise its inherent accuracy, and larger versatility due to being much more powerful, especially when used in revolvers.


.25 Stevens
Serving as the parent for the less-successful .25 Stevens Short and experimental Remington .267 Rimfire, it was dropped in 1942.


.25 Stevens
Notable handgun authority Elmer Keith lamented its demise and advocated its revival for use in revolvers.


.25 Stevens Short
The .25 Stevens Short was an American rimfire rifle cartridge, introduced in 1902.


.25 Stevens Short
Developed by J. Stevens Arms & Tool Company, it was intended to be a lower cost, less potent variant of the .25 Stevens, on which it was based. It initially used a 4.5 to 5 gr (0.29 to 0.32 g) black powder charge; this was later replaced by smokeless. It was offered in Stevens, Remington, and Winchester rifles, and could be used in any .25 Stevens rifle, also (in the way the .38 Special can be fired in weapons chambered for .357 Magnum).


.25 Stevens Short
It was more powerful than the .22 Short, as well as less expensive, but more costly than the .22 Long Rifle and offering no edge in performance. It was also inferior to its parent cartridge. As a result, it was not a popular hunting round.


.25 Winchester Super Short Magnum
The .25 Winchester Super Short Magnum is a third member of the Winchester Super Short Magnum (WSSM) cartridge family created by Winchester and Browning. It is the largest caliber of the WSSM line (excluding wildcats) and is the most capable of handling large game such as deer and wild boar.


.25 Winchester Super Short Magnum, Description
It is a necked-up version of the .243 WSSM, which is in turn a shortened .300 WSM (Winchester Short Magnum). The WSSM cartridges are based on ballistics design philosophies that are intended to produce a high level of efficiency.


.25 Winchester Super Short Magnum, Description
Like other WSSM cases, the .25 is short and fat, which is designed to be more efficient.


.25 Winchester Super Short Magnum, Description
Unlike the other WSSM rounds, the .25 is a magnum in name only, based on the case it uses. Performance wise it is a clone of the .25-06 Remington, making it well suited for medium to large game. The 25 WSSM provides the same performance as the 25-06 Remington, with the advantage of having lighter short action rifles. Having the short fat design, the cartridge loads burn at a more consistent rate, providing a higher level of accuracy. Performance is far less than other .25 caliber magnum rounds as the .257 Weatherby Magnum. In fact, ballistically it's almost identical to the improved version of the .257 Roberts, which P.O. Ackley said was his favorite choice for an all-around cartridge.


.25-06 Remington
The .25-06 Remington had been a wildcat cartridge for half a century before being standardized by Remington in 1969. It is based on the .30-06 Springfield cartridge necked-down (case opening made narrower) to .257 caliber with no other changes. Nominal bullet diameter is 0.257, and bullet weights range from 75 to 120 grains (4.9 to 7.8 g).


.25-06 Remington, History
Charles Newton necked down the .30-06 Springfield cartridge in 1912 to accept the 117-grain .25-35 Winchester bullet. Newton's early modification encouraged commercial release of a shortened case (from 63 to 49mm) as the .250-3000 Savage in 1915. Frankford Arsenal developed an experimental .25-06 during World War I; and distribution of surplus United States military equipment through the Civilian Marksmanship Program following the war encouraged independent gunsmiths to experiment with the cartridge. A. O. Niedner of Dowagiac, Michigan introduced rifles for the .25 Niedner in 1920.


.25-06 Remington, History
Niedner Arms Corporation retained the 17° 30′ .30-06 shoulder chambering .25 caliber barrels rifled with one twist in 12 inches (300 mm). Similar cartridges were identified as the .25 Hi -Power, .25 Whelen (analogous to .35 Whelen), or .25-100-3000 (to indicate the ability to achieve 3000 feet  per second with a 100 grain bullet rather than the 87 grain bullet used in the .250-3000 Savage). Greater case capacity offered minimal velocity improvement over the .250-3000 Savage case with contemporary smokeless powders.


.25-06 Remington, History
Availability of DuPont's Improved Military Rifle (IMR) powders encouraged commercial release of the .257 Roberts using the 57mm-long Mauser case in 1934. Release of IMR 4350 in 1940 and availability of surplus 4831 powder salvaged from Oerlikon 20mm cannon cartridges after World War II greatly improved performance of the full-length .25-06 case.


.25-06 Remington, Performance
The cartridge is capable of propelling a 117 grain (7.6 g) bullet at up to 3,200 feet  per second (980 m/s) and energy levels up to 2,500 ft⋅lbf (3,400 J). Bullets lighter than 75 grains are available in .257 caliber, but were designed for the smaller .25-20 Winchester and .25-35 Winchester cartridges and are too lightly constructed for the high velocities of the .25-06.


.25-06 Remington, Performance
The cartridge has less felt recoil than a .30-06 in a similar weight rifle, due to the lighter weight bullets used. Shooters who are recoil sensitive will find the recoil from the .25-06 bearable, but not pleasant enough to shoot all day long. This cartridge is not quite as powerful as the .257 Weatherby Magnum, usually running 200–300 ft/s (61–91 m/s) slower with a given bullet weight.


.25-06 Remington, Uses
.25-caliber bullets typically have high ballistic coefficients without being heavy. This characteristic, when combined with the large case capacity of its parent .30-06 case, allows relatively high muzzle velocities without heavy recoil. The combination of high ballistic coefficients with high muzzle velocities give the .25-06 a very flat trajectory as well as retaining kinetic energy down-range.


.25-06 Remington, Uses
The .25-06 is generally considered to be a good round for medium-sized game such as deer and antelope because of its combination of substantial kinetic energy and moderate recoil. The addition of a flat trajectory makes it particularly popular in plains states where the open fields can require longer-range shots on game, as this flatness tends to minimize range-estimation errors by the hunter. However bullet types and weights are loaded that allow the .25-06 to be used for taking game ranging from small animals like prairie dogs and coyotes to heavier elk. These bullets range from lightly constructed 75-grain bullets with muzzle velocities in the 3,700 ft/s (1,130 m/s) range to more robust 120-grain bullets with muzzle velocities in the 3,000 ft/s (915 m/s) range.


.25-06 Remington, Uses
Most manufacturers of bolt action or single-shot rifles offer the .25-06 as a standard chambering and factory loaded ammunition is available from Remington, Winchester, Federal Cartridge and most other major manufacturers.


.25-20 Winchester
The .25-20 Winchester, or WCF (Winchester center fire), was developed around 1895 for the Winchester Model 1892 lever action rifle. It was based on necking down the .32-20 Winchester. In the early 20th century, it was a popular small game and varmint round, developing around 1,460 ft/s with 86-grain bullets. But two years earlier Marlin Firearms Co. had already necked down the .32-20 Winchester, and called it the .25-20 Marlin. It was first chambered in Model 1889 lever action Marlins long before Winchester did the same thing and put their name on the .25-20.


.25-20 Winchester
While the SAAMI pressure rating is a full 28,000 CUP, modern ammunition is often loaded lighter in deference to the weaker steels used on many of the original guns. The early black powder cartridges were loaded to about 20,000 psi, but the SAAMI rating is close to that of the high velocity smokeless rounds produced later. The high velocity loadings developed 1,732 ft/s.


.25-20 Winchester
It was easy and economical to reload and was once a favorite with farmers, ranchers, pot hunters, and trappers. Though the .25-20 has been used on deer and even claimed the James Jordan Buck, a whitetail deer of long standing record in 1914, it is now rarely used on large-bodied game due to its sedate ballistics and light bullet construction, which make humane one-shot kills unlikely. Though the higher velocity loads would be destructive for small game use, the handloader can run heavier  cast lead bullets such as the 85 gr. LRNFP at more sedate velocities around 1,000-1,200 FPS to anchor game with much more authority than the .22 Long Rifle, yet not destroy meat. The .25-20 is still a very viable small game, fur bearing and trapping cartridge.


.25-20 Winchester
The .25-20 Winchester is sometimes confused with the similarly named .25-20 Single Shot; the two cartridges are markedly different and do not interchange with one another.


.25-21 Stevens
Designed by Capt. W. L. Carpenter, 9th U.S. Infantry, in 1897, the .25-21 was based on the longer .25-25. It was Stevens' second straight-cased cartridge (after the .25-25) and would be used in the single shot Model 44 rifle, as well as the Model 44½, which first went on sale in 1903. In addition, it was available in the Remington-Hepburn target rifle.


.25-21 Stevens
While the .25-25 was popular, the .25-21 offered "practically the same performance and was a little cleaner shooting." It was also found the usual 20 or 21 gr (1.30 or 1.36 g) black powder charge of the shorter, bottlenecked .25-21 offered "practically the same ballistics" as 24 or 25 gr (1.56 or 1.62 g) in the .25-25. It was highly accurate, reputedly capable of generating .5 in (12.7 mm) groups at 100 yd (91 m).


.25-21 Stevens
In power, the .25-21 was outpaced by the .25-20 Winchester and .32-20 Winchester, while today, even modern pistol rounds such as the .38 Super offer superior performance.


.25-25 Stevens
This is the current revision of this page, as edited by Sauer202 (talk | contribs) at 14:14, 11 April 2020. The present address (URL) is a permanent link to this version.


.25-25 Stevens
Designed by Capt. W. L. Carpenter, 9th U.S. Infantry, in 1895, the .25-25 Stevens was the company's first straight-cased cartridge. It was used in Stevens' single shot Model 44, as well as the Model 44½ rifles, which first went on sale in 1903. In addition, it was available in the Remington-Hepburn target rifle.


.25-25 Stevens
While the .25-25 was popular, the .25-21 offered "practically the same performance and was a little cleaner shooting." It also suffered a "freakish" appearance, due to its length to diameter ratio. It was also found that the usual 20 or 21 gr (1.30 or 1.36 g) black powder charge of the shorter  25-21 offered "practically the same ballistics" as 24 or 25 gr (1.56 or 1.62 g) in the .25-25.


.25-25 Stevens
The switch to smokeless powder only exacerbated the problem, due to the small charge. To cure this, handloaders use a mix of 3 to 5 gr (0.19 to 0.32 g) of bulk shotgun powder and 18 to 20 gr (1.2 to 1.3 g) of black powder, with bullets of between 60 to 86 gr (3.9 to 5.6 g).


.25-25 Stevens
The bore diameter of the .25-25 Stevens is .250 inches (6.35 mm) making it a ".25"/6.35 mm caliber" cartridge, not to be confused with the more well known 6.5 mm bore caliber which uses 6.7 mm/.264" bullets.


.25-35 Winchester
The .25-35 Winchester, or WCF (Winchester Center Fire) was introduced in 1895 by Winchester for the Winchester Model 1894 and Savage Model 99 lever action rifles. The case was based on the .30-30 cartridge.


.25-35 Winchester, Performance
Significantly more powerful than the .25-20 Winchester, the .25-35 WCF can be used to hunt small deer at 200 yards and medium-sized deer at 100 yards; however, some consider it better suited to small predators such as coyotes instead. As a matter of history, some hunters in Canada or the U.S. have used it on moose or elk; this is not advisable today. It was a popular round in the Winchester  Model 1885 High Wall single-shot rifle. No production rifles had been made in .25-35 WCF since 1964 until 2005 when Winchester resumed chambering their Model 94 rifles in this cartridge. Winchester ammunition has kept the cartridge in production in the U.S.A.


.25-35 Winchester, 6.5×52mmR
The 6.5×52mmR is a European cartridge that is a close variant of the .25-35 Winchester. It should not be considered identical to the .25-35 Winchester and is not treated as such by the Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives (CIP), which has released separate specifications for each cartridge. The 6.5x52mmR has its origins in Germany and was introduced by RWS and is chambered in many drilling and single-shot rifles. Any interchangeability between the two cartridges is solely dependent on individual chamber tolerances and should not be assumed.


.25-45 Sharps
The .25-45 Sharps (6.35×45mm) is a firearms cartridge designed by Michael H Blank, then CEO of the Sharps Rifle Company, LLC, as a general hunting cartridge for most North American game, in particular Deer, Antelope, Hogs, and Coyotes. Unlike .300 AAC Blackout which was targeted specifically at the suppressed rifle market, and adapted to hunting, the .25-45 Sharps was designed primarily as a hunting round.


.25-45 Sharps
That is not to say the round does not have tactical applications as its ballistics exceed that of the 5.56x45mm NATO cartridge. The cartridge name is derived from its caliber (.25 inch or 6.35 mm bore, and .257 inch or 6.5 mm bullet) and case length of 45 millimeters (necked-up 5.56×45 mm), as opposed to older hyphenated cartridges that were named for caliber and powder charge. Factory ballistics with the 87 gr (5.6 g) bullet equal those of the original .250-3000 Savage with the same bullet weight.


.250-3000 Savage
The .250-3000 Savage (also known as the .250 Savage) is a rifle cartridge created by Charles Newton in 1915. It was designed to be used in the Savage Model 99 hammerless lever action rifle. The name comes from its original manufacturer, Savage Arms, and the fact that the original load achieved a 3,000 ft/s (910 m/s) velocity with an 87 grain (5.6 g) bullet.


.250-3000 Savage, Background
Charles Newton designed the 250-3000 Savage case to fit the popular Savage Model 99 lever-action rifle. Newton recommended loading 100 grain (6.5 g) bullets at 2800 ft/s (850 m/s); but Savage Arms reduced bullet weight to obtain a velocity of 3,000 ft/s (910 m/s), making it the first American cartridge capable of that velocity. Achieving that velocity may have been the reason for the choice of the light-for-caliber 87 grain (5.6 g) bullet. Newton questioned if the publicity advantages of velocity compensated for reduced penetration of the lighter bullet in larger game animals.


.250-3000 Savage, Background
The cartridge has a pressure limit of 45,000 CUP set by SAAMI. It lacks the power of the bigger .25-06 Remington but provides less noise and less recoil. Performance is very close to the .257 Roberts. Arguably it is a better overall cartridge for hunting than the more popular .30-30, but in recent years has lost ground to the .257 Roberts and flatter-shooting 6mm cartridges such as the .243 Winchester.


.250-3000 Savage, Background
Currently there are very few new firearms being made in .250 Savage. It is an excellent cartridge with moderate recoil for hunting small game on up to deer-sized game.


.250-3000 Savage, Variants
Some varmint hunters use the improved version of this cartridge, known as the .250 Ackley, .250 Improved or .250 Ackley Improved as a dual-purpose intermediate-range cartridge. The .250 Ackley is the same basic cartridge with a steeper shoulder and with the sides blown-out or straightened to increase powder space. This provides a velocity improvement of more than 250 ft/s (76.2 m/s) over standard factory loads.


.255 Jeffery Rook
The .255 Jeffery Rook, also known as the .255 Jeffery Rook Rifle, is an obsolete small bore firearm cartridge.


.255 Jeffery Rook, Overview
The .255 Jeffery Rook is a rimmed centerfire cartridge. It was loaded with both black powder and smokeless powders, usually with a 65 gr (4.2 g) lead solid or hollowpoint bullet at a standard muzzle velocity of 1,200 ft/s (370 m/s).


.255 Jeffery Rook, Overview
The .255 Jeffery Rook was developed by W.J. Jeffery & Co and originally designed for use in rook rifles for hunting small game and target shooting. It gained an excellent reputation for accuracy and was widely used for target shooting before being superseded by the .22 Long Rifle as a miniature target round, and it was also chambered in some single-shot pistols.


.255 Jeffery Rook, Overview
Major Percy Powell-Cotton carried a W.J. Jeffery & Co rook rifle chambered in .255 Jeffery Rook on a number of his expeditions stating it "is often better than the shot-gun for collecting specimens and providing for the pot."


.256 Gibbs Magnum
The .256 Gibbs Magnum is an obsolete rimless bottleneck centerfire rifle cartridge developed by George Gibbs of Bristol and introduced in 1913.


.256 Gibbs Magnum, Overview
The .256 Gibbs Magnum was designed and introduced by George Gibbs in 1913 for use in their own Mauser style sporting rifles. The cartridge was created by reducing the neck of the 6.5×57mm Mauser by 2 mm.


.256 Gibbs Magnum, Overview
The .256 Gibbs Magnum is very similar to, but not interchangeable with, the 6.5×55mm Swedish cartridge.


.256 Gibbs Magnum, Overview
One famous user of the .256 Gibbs Magnum was Denis D. Lyell who used a rifle in this calibre for hunting in Africa.


.256 Newton
The .256 Newton was a high-velocity, rimless centerfire cartridge based on the .30-06 Springfield military cartridge and developed in 1913 by Charles Newton in conjunction with the Western Cartridge Company. To make the .256 Newton cartridge, the .30-06 case was necked down to a caliber of .264 inches, the overall case length was shortened, body taper was increased, the neck was moved back, and the shoulder was given a sharper, 23 degree angle, as opposed to the 17 degree shoulder of the parent cartridge.


.256 Newton
The .256 Newton suffered from a lack of available slow burning powders capable of fully exploiting the large capacity of the parent case. Newton's company went bankrupt after the end of World War I and production of commercially loaded ammunition ceased by 1938.


.256 Newton
After World War II, with a supply of 6.5mm rifles (.264 caliber), the availability of slower burning powders, and inexpensive, surplus .30-06 brass cases, shooters developed the 6.5mm-06 wildcat cartridge by necking down the .30-06 case to 6.5mm (.264 inches). In 1997, the A-Square company standardized the chambering as the 6.5-06 A-Square with the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI). Although substantially similar, the .256 Newton is not interchangeable with the .30-06 parent cartridge, the 6.5-06 wildcat chambering, or the SAAMI standardized 6.5-06 A-Square cartridge.


.256 Winchester Magnum
The .256 Winchester Magnum is a firearms cartridge developed by Winchester, and was produced by necking-down a .357 Magnum cartridge to .257 diameter. It was designed for shooting small game and varmints.


.256 Winchester Magnum, History
Introduced in 1960, Winchester offered ammo and reloading components into the early 1990s. The cartridge was first chambered in the Ruger Hawkeye single shot pistol. The next year (1962) Marlin chambered their Model 62 Levermatic rifle for the new Winchester cartridge. These were the two principal firearms chambered for the .256 Win. Mag. It is now obsolete and only offered as a chambering by custom manufacturers of single-shot firearm barrels such as Match Grade Machine and Bullberry. Previously, the Thompson Center Custom Shop had produced some, before closing its doors in 2010.


.256 Winchester Magnum, Ballistics
From an 8.5 inch pistol barrel the 60 grain .256 Winchester factory load was advertised as having a MV of 2350 fps and ME of 735 ft. lbs. This was 250 fps faster and nearly twice as powerful as the .22 Remington Jet, a varmint cartridge for revolvers that was also based on a necked-down .357 Magnum case.


.256 Winchester Magnum, Ballistics
According to data from the fifth edition of the Hornady Handbook of Cartridge Reloading, handloaders with a .256 rifle can approximately duplicate the Winchester factory load using the Hornady 60 grain Flat Point bullet in front of 15.5 grains of H4227 powder for a MV of 2700 fps. The trajectory of that load looks like this: +2.3 inches at 50 yards, +4.4 inches at 100 yards, 0 at 200 yards, and -26.2 inches at 300 yards.


.256 Winchester Magnum, Ballistics
Winchester offered factory loaded .256 Magnum ammunition (and brass to reloaders) into the beginning of the 1990s. Winchester .256 factory loads used a 60 grain Open Point Expanding bullet at a MV of 2760 fps and ME of 1015 ft. lbs. from a 24-inch rifle barrel. That is about 500 fps faster than Winchester factory loads for the old .25-20 cartridge. At 200 yards the velocity was 1542 fps and the remaining energy was 317 ft. lbs.


.256 Winchester Magnum, Firearms
The .256 Winchester Magnum was chambered in a very small selection of firearms, and never achieved great commercial success. Its firearms included:


.256 Winchester Magnum, Firearms
The 256 Winchester Magnum is also chambered occasionally in custom-built revolvers. Past candidates for this caliber conversion have included Ruger Old Model and New Model Blackhawks, and Smith & Wesson K-frames (Models 10, 14, 15, and 19). Colt produced one Python in this caliber as a prototype and retains it in their museum.


.256 Winchester Magnum, Gallery
.256 Winchester Magnum round next to its parent case, the .357 Magnum.


.257 Roberts
The .257 Roberts, also known as .257 Bob, is a medium-powered .25 caliber rifle cartridge. It has been described as the best compromise between the low recoil and flat trajectory of smaller calibers such as the 5 mm (.22") and 6 mm (.24"), and the higher energy but harder recoil of larger popular hunting calibers, such as the 7 mm (.28") family and the popular 7.62 mm (.30").


.257 Roberts
The bullet diameter of the .257 Roberts is .257 inches (6.5 mm, not to be confused with the more well known 6.5 mm caliber (like 6.5×55 mm, 6.5 Grendel or 6.5 Creedmoor) which uses 6.7 mm (.264") bullets, or the .25 ACP pistol caliber which is 6.35 mm (.251"). The .257 Roberts uses the same caliber bullets as .250 Savage or the more powerful .25-06 Remington.


.257 Roberts, History
Many cartridge designers in the 1920s were creating various 6.35 mm (.25) caliber cartridges. Due to the availability of inexpensive Mauser actions, the 7×57mm Mauser case was a common choice, having near ideal volume capacity for the "quarter-bore" (0.25 in; 6.35 mm) using powders available at that time. Ned Roberts is usually credited with being the designer for this cartridge idea. Eventually in 1934 Remington Arms chose to introduce their own commercial version of such a cartridge, and although it wasn't the exact dimensions of the wildcat made by Roberts, they called it the .257 Roberts.


.257 Roberts, History
From its introduction until the appearance of 6 mm cartridges such as .243 Winchester and 6mm Remington, it was a very popular general purpose cartridge. Today, although surpassed in popularity by other cartridges, it lives on with bolt-action rifles being available from some major manufacturers.


.257 Roberts, Conversion of war-souvenir Japanese Arisaka rifles
Japanese Type 38 Arisaka rifles brought to the United States as wartime souvenirs were sometimes converted by rechambering to utilize more readily available .257 Roberts cartridge cases because commercially produced 6.5×50mm Arisaka cartridges were scarce prior to distribution by Norma Projektilfabrik A/S. The neck of the Roberts case would be slightly enlarged to accept handloaded 6.5 mm bullets. The modified Roberts cases are sometimes known as 6.5×.257 Roberts, although the case headstamp may still indicate .257 Roberts. Neither unmodified .257 Roberts ammunition nor the original 6.5×50mm Arisaka ammunition are suitable for firing in rechambered Arisaka rifles.


.257 Roberts, Performance
With light bullets the .257 produces little recoil and has a flat trajectory suitable for varmint hunting. With heavier bullets it produces more recoil, but is capable of taking all but the largest North American game animals. The original factory load for this is very similar to the .250-3000 Savage.


.257 Roberts, Improved cartridges
Remington introduced the commercial version of this popular wildcat as a low-pressure round. At the time there were many older actions available of questionable strength. With a modern action and handloading, this cartridge is capable of markedly improved performance.


.257 Roberts, Improved cartridges
One of the common improvements is called the .257 Roberts +P which has a SAAMI maximum pressure limit of 58,000 psi (400 MPa) compared to the 54,000 psi (370 MPa) listed for the standard .257 Roberts.


.257 Roberts, Improved cartridges
P.O. Ackley said that the .257 Roberts Ackley Improved was probably the most useful all-around cartridge. The Ackley Improved was a typical change of a steeper shoulder coupled with blown-out sides for more of a straight cartridge, providing greater powder capacity.


.257 Roberts, Comparison
Data below shows sample muzzle velocities and muzzle energies for a 61 cm (24 in) test barrel, except .250-3000 Savage which is for a 56 cm (22 in) test barrel and .257 Weatherby Magnum which is for a 66 cm (26 in) test barrel.


.257 Weatherby Magnum
The .257 Weatherby Magnum is a .257 caliber (6.53 mm) belted bottlenecked cartridge. It is one of the original standard length magnums developed by shortening the .375 H&H Magnum case to approx. 2.5 in (64 mm). Of the cartridges developed by Roy Weatherby, the .257 Weatherby Magnum was known to have been his favorite, and the cartridge currently ranks third in Weatherby cartridge sales, after the .30-378 Weatherby Magnum and the .300 Weatherby Magnum.


.257 Weatherby Magnum
The .257 Weatherby Magnum is one of the flattest shooting commercial cartridges. It is capable of firing a 115 gr (7.5 g) Nosler Ballistic Tip bullet at 3,400 ft/s (1,036 m/s) generating 2,952 ft⋅lbf (4,002 J) of energy which is comparable to factory loadings of the .30-06 Springfield and the .35 Whelen in terms of energy.


.257 Weatherby Magnum
Discrepancies between the metric and U.S. diameters of the bullet may cause some confusion. A .257 bullet has a metric bullet diameter of 6.53 mm. However, in Europe cartridge designation nomenclature for a large part relies on the bore diameter. As the bore diameter of the .257 Weatherby Magnum is .250 inches this would make it a 6.35 mm caliber cartridge which uses 6.5 mm bullets (not to be confused with 6.5 mm caliber cartridges which use 6.7 mm/.264" bullets).


.257 Weatherby Magnum, Cartridge history
The .257 Weatherby Magnum was designed in 1944 and introduced commercially in 1945 by Roy Weatherby as a wildcat cartridge as a chambering in his rifles. The 257 Weatherby Magnum is one of Roy Weatherby's favorite calibers. The original cartridge was developed using the H&H Super 30 (a close variant of the .300 H&H Magnum which in turn is based on the .375 H&H Magnum) shortened, blown out, and necked down to accept a .25 caliber (6.35 mm) bullet. Together with the .270 Weatherby Magnum, the 7mm Weatherby Magnum, and the .300 Weatherby Magnum, the .257 Weatherby Magnum were the earliest cartridges introduced by Roy Weatherby.


.257 Weatherby Magnum, Cartridge history
The original cartridges were formed using Winchester's .300 H&H Magnum (H&H Super 30) and was only available as a component from Weatherby. Beginning in 1948 Weatherby began offering loaded ammunition for the .257 Weatherby Magnum cartridge which was loaded in house. Until then the cartridge was only available as a component brass which would require being loaded before use. Sometime later, the .257 Weatherby brass was manufactured by Richard Speer for Weatherby. However, due to space and organizational constraints Weatherby began looking for a source of ammunition for his cartridge.


.257 Weatherby Magnum, Cartridge history
The search culminated in 1951 with Norma Projektilfabrik being awarded a contract to produce ammunition. Since then, all Weatherby Ammunition has been manufactured by Norma with the exception of a brief period of time between 1963 and 1964 when production moved to RWS/Dynamit-Nobel, a company which had entered into partnership with Weatherby.


.257 Weatherby Magnum, Cartridge history
Ever since the release of the .257 Weatherby Magnum it has remained one of the more popular cartridges in terms of Weatherby sales. Gun writers such as Layne Simpson consider the .257 Weatherby one of his favorite long range cartridges.


.257 Weatherby Magnum, Design and specifications
The .257 Weatherby Magnum shares the same cartridge case as the .270 Weatherby Magnum and the 7mm Weatherby Magnum. The .30 Super Belted Rimless H&H manufactured by Winchester served as the direct parent cartridge for the case design. The .257 Weatherby Magnum was one of the first cartridges which used the shortened, blown out and necked down .375 H&H Magnum case and served as the forerunner to the standard length magnum cartridges such as the 7mm Remington Magnum and the .338 Winchester Magnum.


.257 Weatherby Magnum, Design and specifications
There has been some speculation that Roy Weatherby may have used the full length .375 H&H Magnum case if he had slow burning powders available today when the cartridge was designed. The shortening of the case allowed for the more efficient use of the slow powder of the day, IMR 4350; a powder which would not have provided any great advantage for such cartridges as the .257 Weatherby Magnum or the .270 Weatherby Magnum if such cartridges utilized the full length H&H case. Today, IMR 4350 is considered too fast a burning propellant for the cartridge which comes into its own with the slowest burning powders now available.


.257 Weatherby Magnum, Design and specifications
Both SAAMI and the CIP have published specification for the cartridge. The CIP standards for the cartridge were published in January 1994.


.257 Weatherby Magnum, Design and specifications
SAAMI recommends a barrel rifling contour of 6 grooves with a bore Ø of .2505 in (6.36 mm) and a groove Ø of .257 in (6.5 mm) with each groove being .098 in (2.5 mm) wide. The recommended optional twist rate is one revolution in 10 in (250 mm). Both SAAMI and Weatherby recommend a freebore of .378 in (9.6 mm). Early .257 Weatherby rifles has a twist rate of 1 revolution in 12 in (300 mm) but all current rifles are manufactured with a twist rate of 1 revolution in 10 in (250 mm).


.257 Weatherby Magnum, Design and specifications
The .257 Weatherby Magnum has a case capacity of 84 gr. of water (5.45 cm3). Sources such as Lyman and Weatherby's pressure rating suggest maximum average pressure limit of 66,000 psi (4,600 bar). CIP limits the .257 Weatherby Magnum to a maximum average pressure of 4,400 bar (64,000 psi).


.257 Weatherby Magnum, Design and specifications
The .257 Weatherby Magnum features the Weatherby double radius shoulder. The shoulder continuously curves and transitions from the body radius to the neck radius at the point of tangency at the shoulder between the two radii. The SAAMI dimensions for the cartridge reflect this implementation of shoulder to neck transition. While the CIP recognizes the correct radii for both the r1 and r2 values, they treat the transition from the body to shoulder and neck to shoulder as filet radii. For this reason the body and neck dimensions are lengthened and a shoulder angle provided. The treatment of the body-shoulder-neck transition zone accounts for the inconsistencies between SAAMI and CIP official dimensions for the cartridge.


.257 Weatherby Magnum, Performance
The .257 Weatherby is known for its long range performance and is considered an accurate flat shooting cartridge. Initially due to the cartridge's high velocity the cartridge exhibits less bullet drop than most other cartridges. However, due to lower ballistic coefficients of these bullets, velocity (and therefore energy) is shed more quickly.


.257 Weatherby Magnum, Performance
Weatherby's B25780TTSX, B257100TSX and the N257115BST ammunition have point blank ranges of 369 yd (337 m), 350 yd (320 m) and 323 yd (295 m) respectively. Thus no hold over is necessary when shooting at game at these ranges given that the rifles is zeroed correctly to accomplish this task.


.257 Weatherby Magnum, Performance
The .257 Weatherby offers a 300–400 ft/s (91–122 m/s) over the 25-06 Remington cartridge which translates to around 600 ft⋅lbf (810 J) greater energy than the latter cartridge. Comparing the Remington's Premium PRC2506RA ammunition for the 25-06 Remington Weatherby's N257115BST .257 Weatherby bullet when zeroed for 200 yd (180 m) drops less than 30 in (76 cm) while the 25-06 Remington drop slightly over 44 in (110 cm) at 500 yd (460 m).


.257 Weatherby Magnum, Performance
When sighted in for 300 yd (270 m) the bullet of Weatherby's N257115BST ammunition has only dropped 21.9 in (56 cm) at 500 yd (460 m) and retains 1,347 ft⋅lbf (1,826 J) energy. Compared to the Winchester's .270 WSM SXP270S ammunition show a bullet drop of 24.5 in (62 cm) but retains 1,552 ft⋅lbf (2,104 J). The N257115BST bullet retains enough energy to be effective on deer out to 550 yd (500 m) while the SXP270S's bullet extends this range out by a further 100 yd (91 m) although both the Weatherby's and Winchester's ammunition start with roughly the same muzzle energy.


.257 Weatherby Magnum, Performance
Weatherby guarantees a 1.5 MOA accuracy with their ammunition in a Weatherby rifle, .99 MOA or better with their Sub-MOA Vanguard rifles, and .99 MOA or better with the new Vanguard Series 2 Rifles.


.257 Weatherby Magnum, Sporting usage
The .257 Weatherby is a hunting cartridge and has not, to a significant extent, been adopted into any other shooting discipline. Due to the cartridge's use of lighter bullets of a quarter bore diameter it should be restricted to medium game species. The cartridge comes into its own where shooting over long distances is anticipated. This is especially true in major grasslands such as prairies, steppes, Pampas, or savannah; or in mountainous terrain such as the Rockies, Alps or the Himalayas.


.257 Weatherby Magnum, Sporting usage
The .257 Weatherby makes an ideal pronghorn cartridge. Due to the habitat of the species and its wariness, shooting distances are generally longer than for other species in North America. The typical pronghorn weighs less than 175 lb (79 kg) and as a small bodied ungulate does not require bullets with a great penetrative ability. Bullets which open quickly and have a weight ranging between 95–110 gr (6.2–7.1 g) such as the Nosler Ballistic Tip bullet are excellent choices for this game species.


.257 Weatherby Magnum, Sporting usage
The cartridge is an excellent choice for smaller deer species such as whitetail and mule deer. These deer species are typically larger and tougher than the pronghorn antelope and may require a slightly heavier bullet. Bullets ranging in weight from 100 gr (6.5 g) to 115 gr (7.5 g) should be chosen for these deer species. Although the .257 Weatherby is used as an elk and moose cartridge with success in North America, the cartridge is thought of as being ill-suited for these heavier deer, with elk weighing on average 700 lb (320 kg) and moose on average between 1,000–1,400 lb (450–640 kg), depending on subspecies.


.257 Weatherby Magnum, Sporting usage
The cartridge has had success against mountain sheep and goat whether it be in the Alps, Rockies, Caucasus, Pamir or the Himalayas. Shooting distances are typically long, and the .257 Weatherby is able to reach out to the long ranges required to take the game.


.257 Weatherby Magnum, Sporting usage
Should the cartridge be employed for plains game in Africa, use should be restricted to game species under 440 lb (200 kg). The cartridge is effective against smaller plains game species such as gemsbok, waterbuck, nyala and impala.


.257 Weatherby Magnum, Sporting usage
The .257 Weatherby is used as an ideal small predator cartridge for animals such as lynx, cougar, bobcat, fox, coyote, and wolverine, all of which are taken yearly with the cartridge. While the .257 Weatherby can be employed as an effective varmint round, the cost per cartridge and the muzzle blast precludes its use as a varmint cartridge in large numbers. Furthermore, barrel heating and wear are a consideration when employing the .257 Weatherby for such duties where one would shoot long strings of shots in a short period of time.


.257 Weatherby Magnum, Sporting usage
Due to the cartridge's high velocity and use of lightly constructed bullets, the use of the cartridge as a small game cartridge is not recommended as there are far better choices available which do not destroy the meat as the .257 Weatherby does. If solids or FMJ bullets are used this should not be an issue with regard to small game intended for the table.


.257 Weatherby Magnum, Sporting usage
Roy Weatherby took the .257 Weatherby Magnum to Africa and took an African Cape buffalo with a single shot to prove to himself that it could be done. Although the cartridge has been used against lion and bears, the cartridge is ill-suited for dangerous game species as it lacks bullets with good weights and sectional densities to be considered an even moderately effective cartridge against such game.


.257 Weatherby Magnum, Rifles and ammunition
Weatherby continues to chamber the .257 Weatherby Magnum in several models based on both the Mark V and Vanguard action types. The Weatherby Custom Shop offers a more personalized rifle based on these actions. Remington Arms manufactures released the Special Editions of the Model 700 CDL SF and the Model 700 LSS in 2008. The Weatherby rifles have deeply blued barrels while the Remington rifles have matte stainless steel barrels.


.257 Weatherby Magnum, Rifles and ammunition
Weatherby rifle ammunition for the .257 Weatherby Magnum is manufactured by Norma of Sweden. Conley Precision Cartridge Company manufactures several premium lines of .257 Weatherby ammunition using Barnes, Nosler, Speer, Swift and Trophy Bonded bullets. Double Tap ammunition also offers loaded ammunition for sale.


.257 Weatherby Magnum, Rifles and ammunition
The 120 gr (7.8 g) Weatherby N257120PT ammunition should not be used in older .257 Weatherby rifles as the twist rate is too slow to adequately stabilize the bullet. The 117 gr (7.6 g) Weatherby H257117RN ammunition is manufactured for rifles with the slower twist rate.


.257 Weatherby Magnum, Criticism
The .257 Weatherby Magnum is one of the most overbore cartridges available. The cartridge rates higher on the overbore index than the .264 Winchester Magnum and the 7mm Shooting Times Westerner but less than the 7mm RUM and the .30-378 Weatherby Magnum. The consequence of burning a large quantity of powder and driving a bullet faster is poor barrel life and throat erosion all of which affects accuracy and usable life of the firearm.


.257 Weatherby Magnum, Criticism
Giving the barrel time to cool between each discharge of the weapon and following recommended cleaning procedures will help mitigate this issue and extend the usable life of the firearm chambered for this cartridge. Stainless steel barrels can further extend the barrel life of rifles chambered in the 257 Weatherby Magnum.


.257 Weatherby Magnum, Criticism
Earlier .257 Weatherby Magnum rifles had a twist rate of 1 rotation in 12 in (300 mm), which is too slow to stabilize long for caliber bullet. These bullets include most Barnes' bullets over 110 gr (7.1 g) and any conventional spitzer bullet of over 115 gr (7.5 g). Hornady's 117 gr (7.6 g) round nose bullet is made for such firearms which have the slower spin rate. Norma loads this bullet in the Weatherby's H257117RN ammunition for owner of such rifles who require a heavier bullet.


.260 Remington
The .260 Remington (also known as 6.5-08 A-Square) cartridge was introduced by Remington in 1997. Many wildcat cartridges based on the .308 Winchester case had existed for years before Remington standardized this round.


.260 Remington
Because 6.5 mm (.264") bullets have relatively high ballistic coefficients, the .260 Remington has seen success in rifle competition including bench rest, metallic silhouette, and long range. It is capable of duplicating the trajectory of the .300 Winchester Magnum, while generating significantly lower recoil. Also, converting a rifle chambered for the .308 Winchester (or any of its offspring, such as the .243 Winchester, 7mm-08 Remington, .358 Winchester or .338 Federal) to .260 Remington generally requires little more than a simple barrel change.


.260 Remington, Origin and history
Remington has had a track record of adopting successful wildcat cartridges into the Remington fold by offering rifles and ammunition and at times attaching their name to the cartridge. Like many cartridges such as the .22–250 Remington, .25-06 Remington, and 7 mm-08 Remington. The .260 Remington started its life as a wildcat cartridge called the 6.5-08, and was eventually released as a commercial cartridge by Remington. However, Remington was not the first to attempt to standardize the cartridge. LTC Arthur Alphin and his company A-Square LLC submitted the first proposal and drawings to SAAMI for the standardization of the cartridge. Remington filed similar papers with SAAMI to do the same a few months later. When the dust settled, the 6.5-08 would be called the .260 Remington instead of 6.5–08 A-Square.


.260 Remington, Origin and history
The 6.5-08 cartridge was created simply by necking down the .308 Winchester. Handloaders and wildcatters can easily form .260 cases by necking down the 7mm-08 Remington or necking up the .243 Winchester (both based on the same .308 case). Since the parent cartridges were readily available for low cost, the 6.5-08 was often an economical alternative to cartridges such as the 6.5×55mm. What the 6.5-08 provided over the .243 Winchester, .308 Winchester, and to a lesser degree the 7mm-08 Remington was bullets with excellent ballistic coefficients and sectional densities.


.260 Remington, Origin and history
Since the 6.5-08 was a wildcat cartridge, variations existed between cartridge chambers depending on the reamer used to cut the chamber. Furthermore, depending on whether one chose to form the case from .243 Winchester or .308 Winchester influenced the neck thickness and therefore the dimensions of the cartridge. A cartridge formed for a specific rifle may or may not successfully chamber or worse may reach dangerous pressures in another. Standardizing the cartridge addressed the issues owners experienced when it was a wildcat.


.260 Remington, Origin and history
.264 (6.5 mm) caliber has historically been commercially unsuccessful in North America but has been one of the mainstays in Europe especially in the Scandinavian countries. The 6.5×54mm Mannlicher–Schönauer, 6.5×55mm, 6.5×57 Mauser, and 6.5-284 Norma have loyal followings in Europe. Starting with the .264 Winchester Magnum and later the 6.5mm Remington Magnum, North American cartridges in this caliber have been largely failures.


.260 Remington, Origin and history
The .260 Remington appeared to be following this North American trend, with Remington only producing the Model Seven Synthetic in the .260 Remington for 2011 as it has discontinued such rifles as the Model 700 CDL and the Model Seven (including the youth model) in .260. However, Remington continues to manufacture several types of .260 Remington loads. The use of the .260 Remington by Sgt Sherri Gallagher to win the 2010 NRA High Power National Championship has sparked a resurgence in the round, and Lapua announced at the 2011 SHOT show that it would be manufacturing .260 Remington brass.


.260 Remington, Design and specifications
The .260 Remington uses the .308 Winchester case as its parent cartridge which is simply necked down to accept a .264 caliber bullet with no further changes made to the case. As the cartridge follows a modern design, it has little taper which allowed its parent cartridge to feed reliably through auto-loading rifles such as the M14, FN FAL and the H&K G3. The .260 Remington has a case capacity of about 3.47 ml (53.5 grains) H2O.


.260 Remington, Design and specifications
Both SAAMI and C.I.P. have provided design specifications for the .260 Remington cartridge. While there are minor dimensional differences between dimensions provided by both organizations, these dimensional differences mostly fall within the tolerances allowed by the other organization, though C.I.P. lists the .260 as a Delta L problem cartridge. SAAMI dimensions for the cartridge were issued on January 29, 1999, when the Remington's submission was accepted.


.260 Remington, Design and specifications, SAAMI specifications
SAAMI recommends a barrel with a 6 groove contour and a twist rate of one revolution every 9 in (229 mm) with each groove having a width of .095 in (2.41 mm). The recommended bore diameter is .256 in (6.50 mm) and the groove diameter is .264 in (6.71 mm). SAAMI recommends that rifling commence at .221 in (5.61 mm) from the chamber mouth. SAAMI also recommends a pressure of 60,000 psi (413.69 MPa)


.260 Remington, Design and specifications, C.I.P. specifications
.260 Remington maximum C.I.P. cartridge dimensions. All sizes in millimeters (mm) plus Imperial (inches).


.260 Remington, Design and specifications, C.I.P. specifications
Americans would define the shoulder angle at alpha/2 = 20 degrees. The common rifling twist rate for this cartridge is 229 mm (1 in 9 in), 6 grooves, Ø lands = 6.50 mm (0.256 in), Ø grooves = 6.71 mm (0.264 in), land width = 2.42 mm (0.095 in) and the primer type is large rifle.


.260 Remington, Design and specifications, C.I.P. specifications
According to the official C.I.P. (Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives) rulings, the .260 Remington case can handle up to 415 MPa (60,191 psi) piezo pressure. In C.I.P. regulated countries every rifle cartridge combo has to be proofed at 125% of this maximum C.I.P. pressure to certify for sale to consumers.


.260 Remington, Performance
The .260 Remington being a .264 caliber (6.5 mm) has certain advantages: the bullets have good sectional density (penetrating ability) and a good selection of bullet weights. Factory ammunition usually are loaded with bullets weighing anywhere from 120 gr (7.8 g) to 140 gr (9.1 g). Bullets available to the reloader range from 85 gr (5.5 g) to 160 gr (10 g). The 120 gr (7.8 g) bullet has a sectional density of 0.246 which is similar to a 165 gr (10.7 g) .308 caliber (7.62 mm) bullet.


.260 Remington, Performance
The 140 gr (9.1 g) bullet has a sectional density of 0.287 which is similar to that of a 190 gr (12 g) .308 caliber (7.62 mm) bullet. The 160 gr (10 g) bullet which has a sectional density of 0.328 is similar in sectional density to a 220 gr (14 g) .308 caliber (7.62 mm) bullet. As sectional density plays a large factor in penetration, the .264 caliber (6.5 mm), though a diminutive caliber from a North American point of view, has had excellent results in the field. Walter D.M. Bell, who was known to have shot over a thousand elephants in his lifetime, used, among others, .264 caliber (6.5 mm) and .284 caliber (7 mm) rifles to do so.


.260 Remington, Performance
The .260 Remington, while having a slightly lesser case capacity than the 6.5×55mm, is loaded to higher pressure levels.


.260 Remington, Performance
The opposite is true when comparing the .260 Remington to the 6.5mm Creedmoor: They are nearly-identical but the Creedmoor can take a higher chamber pressure than the .260 Remington, leading the Creedmoor to have more room for a longer bullet (more aerodynamically efficient, higher sectional density than most shorter bullets) in a given magazine length or cartridge overall length than the .260 Remington's maximum projectile length or ogive length, and yet the .260 Remington only has a similar muzzle velocities as the 6.5 Creedmoor for a given projectile weight, despite the .260 Remington's larger case capacity and longer brass casing.


.260 Remington, Performance
However, for the same reasons (higher chamber pressure than the 6.5x55 Swede and shorter brass casing), the .260 Remington outperforms the 6.5x55 Swede. Typically, the .260 Remington is loaded with a 120 gr (7.8 g) bullet at 2,890 ft/s (880 m/s) and the 140 gr (9.1 g) bullet at 2,750 ft/s (840 m/s). In contrast, Norma of Sweden loads the 6.5×55mm with a 120 gr (7.8 g) bullet at 2,822 ft/s (860 m/s) and the 140 gr (9.1 g) bullet at 2,690 ft/s (820 m/s).


.260 Remington, Performance
While it is possible to load the 160 gr (10 g) bullet which is popular in Northern Europe, for the .260 Remington, due to the comparatively short overall length of the cartridge, the bullet will need to be seated deep into the body of the cartridge, displacing space which could be taken up by the propellant. For this reason, bullets weighing over 140 gr (9.1 g) are not generally recommended for loading with this cartridge.


.260 Remington, Sporting usage
Due in large part to its parentage, the .260 Remington has been adopted into tactical and target shooting rifles. Any rifle which is chambered for 7.62×51mm NATO or .308 Winchester can be converted with only the addition of an appropriate barrel to the .260 Remington. Companies such as Lewis Machine & Tool (LMT) ArmaLite, LaRue, DPMS Panther Arms, McMillan Firearms (makers of the Tubb 2000), and KMW are among several companies which currently manufacture tactical rifles for use with this cartridge. The 6.5 mm (.264 caliber) bullets have favorable ballistic coefficients and have been adopted for target shooting, especially in the Scandinavian nations. Tubbs manufactures rifles for competition one of which went on to win the NRA HP Championship in 2010.


.260 Remington, Sporting usage
The .260 Remington has become popular with metallic silhouette shooters. The 2014 NRA National Championship equipment survey lists the .260 Remington as most popular caliber for both the high power rifle and high power hunter rifle competition.


.260 Remington, Sporting usage
The .260 Remington is effective on antelope, sheep, goat, or caribou, while its performance is similar to the 6.5×55mm, which is widely used on moose in Sweden and Finland. While capable of taking Class 3 game such as elk and moose, some hunters, particularly Canadian professional hunters who hunt large moose and elk, consider it slightly underpowered for these species and best used for smaller deer species such as white-tail and mule deer.


.260 Remington, Sporting usage
The 6.5×55mm, which is usually loaded to a lower power level than the .260 Remington, is commonly used in Norway and Sweden with bullets weighing at least 9 g (140 gr) to kill Eurasian elk (a term which is applied to moose in these countries). The .260 Remington would make an excellent cartridge for hunting Class 2 species such as the smaller African antelope weighing 440 lb (200 kg) or less.


.260 Remington, Sporting usage
Loaded with lighter bullets, the .260 Remington can be used as an effective varmint or a small predator hunting cartridge for use against such species as marmots, woodchucks, bobcats and coyotes. Bullets chosen for these species should be designed to open rapidly unless harvesting of the pelt is the objective. FMJ or other non-expanding bullets can be used if the latter is the case.


.260 Remington, Sporting usage
The .260 Remington, loaded with very low drag bullets such as the 138 gr (8.9 g) Lapua, 140 gr (9.1 g) Berger, or 142 gr (9.2 g) Sierra, can match the 1,000 yd (910 m) performance of the 190 gr (12 g) Sierra-loaded .300 Winchester Magnum, with better resistance to wind deflection and half the recoil. With a 120 gr (7.8 g) boattail, energy remaining at 400 yd (370 m) is comparable to a 180 gr (12 g) in .308 Winchester, while generating only about three-quarters the recoil.


.260 Remington, Rifles and ammunition
When the .260 Remington was introduced, Remington chambered the cartridge in both the Model 700 (BDL and CDL)  and the Model Seven (CDL and Youth) rifles. Remington also offered the cartridge in a Law Enforcement (LE) only model of the Model 700 rifle. While Remington has discontinued the chambering of the .260 Remington in these models, the Remington Custom Shop continues to produce rifles chambered for the cartridge.


.260 Remington, Rifles and ammunition
Browning at one time chambered the cartridge in their copy of the Winchester 1885 Low Wall rifle which Browning markets as the B78 and also their A-Bolt Micro Hunter rifle. Browning has since discontinued the .260 Remington chambering in these models.


.260 Remington, Rifles and ammunition
Savage Arms continues to manufacture several rifles chambered for the .260 Remington. Currently they offer the Hunter Series 11 FCNS, Weather Warrior Series 16 FCSS, and the Target Series Model 12Long Range Precision rifle. Savage also chambers the cartridge in more specialized rifles such as the Model 10 Predator Hunter Max 1, Model 11 Lightweight Hunter and the Model 11 Long Range Hunter.


.260 Remington, Rifles and ammunition
Lewis Machine & Tool offers 260 Remington Barrels for the MWS series of rifles which allow the operator to quickly change barrel from several different calibers.


.260 Remington, Rifles and ammunition
Tikka offers multiple variants of its T3 series of rifles chambered in .260 Remington.


.260 Remington, Rifles and ammunition
The SAKO TRG 22 competition and sniper rifle is available in .260 Remington.


.260 Remington, Rifles and ammunition
LaRue has released their PredatOBR (AR-10 style rifle) chambered in .260 as well.


.260 Remington, Controversy
The cartridge that is now popularly known as the .260 Remington was submitted for standardization under SAAMI by the A-Square Company in 1996, several months prior to Remington announcing their plans to introduce the cartridge under their own name. A-Square's submission was called the 6.5-08 A-Square. Some users continue to refer to the cartridge under this name.


.260 Remington, Controversy
Since the acceptance of the submission by Remington Arms for the standardization of the 6.5-08 cartridge by SAAMI, A-Square has dropped the cartridge from their line of cartridges chambered for their rifles and no longer offers ammunition in this cartridge. Instead A-Square LLC has gone on to produce rifles and ammunition for the 6.5-06 A-Square cartridge which is based on the .30-06 Springfield necked down to .264 caliber (6.5 mm). This cartridge provides over a 200 ft/s (61 m/s) velocity advantage over the .260 Remington.


.264 Winchester Magnum
The .264 Winchester Magnum is a belted, bottlenecked rifle cartridge. Except for the .244 H&H Magnum and .257 Weatherby Magnum, it is the smallest caliber factory cartridge derived from the 2.85 in (72 mm) Holland & Holland belted magnum case. It was introduced in the late 1950s and early 1960s with the .338 Winchester Magnum and the .458 Winchester Magnum as one of a family of short-cased 2.5 in (64 mm) belted magnum cartridges developed by Winchester based on the .375 Holland & Holland parent case. It was officially introduced to the public by Winchester in 1959.


.264 Winchester Magnum
After many years of dwindling use it began enjoying a mild resurgence in popularity in the mid-2000s among long range rifle enthusiasts and reloaders due to the high ballistic coefficient of the heavier 6.5mm bullets and increasing popularity of cartridges such as 6.5mm Creedmoor, .260 Remington, 6.5 Grendel, benchrest and wildcat cartridges in 6.5mm.


.264 Winchester Magnum, Design & specifications
Winchester had been manufacturing the shortened Holland & Holland cases under a contract for Weatherby for use in their .257 Weatherby Magnum, .270 Weatherby Magnum and 7mm Weatherby Magnum cartridges. The Weatherby cases had been based on Winchester's .30 Super cartridge. This new series of shortened Holland & Holland cases was based on the .375 Holland & Holland case. The advantages of the shortened case were twofold: the cartridge could function through the standard length rifle action as used by the popular .30-06 Springfield and .270 Winchester.


.264 Winchester Magnum, Design & specifications
It was also close to the efficiency limitations of powders available at the time given the case capacity of the cartridge. The longer, full length .375 H&H case would not have resulted in a great performance improvement due to the powders available at that time. It was similar to the reasoning behind the shortened cases used by Weatherby as DuPont's IMR 4350 was the slowest burning powder available then.


.264 Winchester Magnum, Design & specifications
The .264 Winchester Magnum is a cartridge which was standardized by SAAMI, which published recommended specifications for the cartridge. SAAMI recommends a six groove barrel with a rate of twist of one revolution in 9 in (230 mm), a bore diameter of .256 in (6.5 mm) and a groove diameter of .264 in (6.7 mm) with each groove having a width of 0.090 in (2.3 mm). The recommended maximum pressure for the cartridge (piezo) is 64,000 psi (4,400 bar).


.264 Winchester Magnum, Performance
The .264 Winchester Magnum gained a reputation as a very flat shooting cartridge. When introduced, it was first chambered in the Winchester Model 70 Westerner rifle, which was intended for longer range shooting more common in the Western United States.


.264 Winchester Magnum, Performance
At present Remington, Winchester, HSM, and DoubleTap Ammunition produce ammunition for this cartridge. Manufacturers offer a 140 gr (9.1 g) bullet at 3,030 ft/s (920 m/s). This ammunition has a maximum point blank range of 300 yd (270 m) when sighted in at 250 yd (230 m). Some ammunition offers premium 140 gr (9.1 g) Nosler Partition and 125 gr (8.1 g) Accubond bullets driven at 3,100 ft/s (940 m/s) and 3,250 ft/s (990 m/s) through a 24-inch (610 mm) barrel.


.264 Winchester Magnum, Performance
While readily available factory ammunition for the cartridge is for the most part fairly basic, handloaders can gain a step up in performance with bullets with better ballistic coefficients and weights to extend the performance of the cartridge. For this reason, this cartridge is better suited for shooters who are willing to make their own ammunition rather than those who purchase over the counter ammunition.


.264 Winchester Magnum, Reception
The .264 Winchester Magnum main competition comes from the various 7mm cartridges such as the 7mm Remington Magnum, 7mm Weatherby Magnum, the .270 Winchester Short Magnum, .270 Weatherby Magnum, 6.5mm Remington Magnum and the .257 Weatherby Magnum cartridges in North America and the cartridges such as the 6.5×68mm in Europe. Due to the over crowded nature of the market in which the cartridge competes, popularity has been on the wane. In particular, the 7mm Remington Magnum release in 1962 led to the cartridge's poor reception by the shooting public.


.264 Winchester Magnum, Reception
The 7mm Remington Magnum shoots almost as flat as the .264 Winchester Magnum but launches a larger diameter, heavier bullet generating more energy than the .264 Winchester Magnum. Furthermore, the 7mm Remington Magnum benefits from a vast range of compatible bullets due in large part to the popularity of the 7mm caliber while the .264 was something of an oddity and a rather new caliber in North America.


.264 Winchester Magnum, Reception
Ballistically it is almost identical to the 6.5×68mm (also known incorrectly as the 6.5×68 RWS, 6.5×68 Schüler or the 6.5×68 Express Vom Hofe) and the 6.5×63 Messner Magnum.


.264 Winchester Magnum, Reception
The .264 Winchester Magnum is an excellent, potentially accurate, very flat-shooting cartridge capable of taking any game in the lower 48 US states, and one of the most powerful of all .264 in (6.7 mm) cartridges. When loaded with 140 gr (9.1 g) bullets at a muzzle velocity of 3,100 ft/s (940 m/s) it is an adequate round for deer out to beyond 500 yards (460 m) provided that the hunter is capable of such longer shots.


.264 Winchester Magnum, Background
The .264 Win. Mag., like many magnum rounds, can wear out barrel throats more rapidly than lower pressure and lower velocity non-magnum cartridges, especially when fired rapidly, which heats up the steel and hastens throat erosion. Throat erosion is greater in higher chamber pressure overbore cartridges. This was particularly true in the 1950s to early 1960s, with the chrome moly steels almost universally used for barrels then. But recent advances with stainless steel barrels, especially with cryogenic treatment, have extended barrel life considerably with the .264 Win. Mag. and many other cartridges.


.264 Winchester Magnum, Background
While very few production line riflemakers currently offer the .264 Win. Mag. as a factory chambering, the caliber remains popular with some enthusiasts using custom built rifles and handloading their own ammunition, as an internet search shows. As of 2018 and 2019, Winchester is once again producing its M70 bolt-action rifle in .264 Winchester Magnum.


.264 Winchester Magnum, Background
The introduction of Remington's 7 mm Magnum in 1962 almost immediately eclipsed the .264 Win. Mag., even though the 264 Win. Mag. uses an identical brass cartridge case (the neck diameter of either cartridge case can easily be modified to accept the others' bullets by the handloader), it never fully recovered from the competition of the slightly larger-bore cartridge.


.264 Winchester Magnum, Background
The fact that the 7 mm Rem. Mag. thoroughly eclipsed its popularity has been attributed to many causes, the premature "burning out" of barrels as compared to the Remington cartridge often cited. More likely is the fact that hunters had more confidence in the game-getting ability of heavier 7 mm (.284") 150 to 175 grain spitzer-shaped projectiles on big game, as compared to 140 grains being the upper end of pointed .264 bullets.


.264 Winchester Magnum, Background
Conversely, Winchester marketed the .264 as a long range, combination varmint and deer round, although suited for harvesting elk or moose. Unfortunately, the recoil it generates, plus the expense of the sheer quantity of ammo that may be used to shoot pests at long range (compared to pure varmint cartridges like the .222 Remington and the .220 Swift, or the smaller varmint / deer rounds, like the .243 Winchester) inhibited its popularity further.


.264 Winchester Magnum, Background
The result was more sportsmen opting for the bigger Remington 7 mm round because it was seen as more effective on a wider variety of big game; rather than a compromise round that could be used for varmints, worked well on whitetail and mule deer, but was borderline for the largest North American big game when the need arose.


.264 Winchester Magnum, Background
In Europe, two of the .264 Win. Mag. 's champions were George Swenson of John Wilkes gunmakers, London, and David Lloyd of Northampton, England. Lloyd built a number of his deluxe Lloyd rifles in .264 Win Mag, mainly for sportsmen seeking a cartridge that would give high velocity performance with bullets heavier than the 100 grains fired by the .244 H&H Magnum.


.270 British
The .270 British (or .270 Enfield) is an experimental intermediate rifle cartridge that was developed by the British at the same time as the .280 British as a potential successor to the .303 British cartridge. The rimless cartridge has a base diameter of 11.3 mm (like the Russian 7.62×39mm) and a case length of 46 mm. The bullet is a standard .270/.277 caliber bullet with a light 100 gr weight with a muzzle velocity of 840 m/s (2,800 ft/s). It was not good at long range, but its slender case had the potential to fire a heavier bullet at a relatively high velocity. It was optimized for shorter ranges, while the .280 favored long-range performance to try to meet U.S. requirements.


.270 British
The cartridge was not adopted, the British initially focused development on the .270, then ultimately chose the NATO-standard 7.62×51mm cartridge.


.270 Weatherby Magnum
The .270 Weatherby Magnum was the first belted magnum based on the .300 H&H Magnum to be developed by Roy Weatherby in 1943. The cartridge is short enough to function in standard-length long actions with a brass length of 2.549" or 64.74mm and an overall length of about 3.295". It has the characteristic double-radius shoulders and is necked down to accommodate the .277 in bullets. Like most Weatherby cartridges, the .270 Weatherby was standardized by the Small Arms and Ammunitions Manufacturers Institute in 1994, and it has a SAAMI maximum pressure limit of 62,500 psi. The first Weatherby cartridge to be used in Africa was the .270 Weatherby on a jackal on June 8, 1948.