What is the name for the helical grooves in the barrel of a gun designed to impart spin on the projectile to improve its aerodynamic stability and accuracy?
Gun barrel energy during the firing process. The projectile’s status of motion while travelling down the bore is referred to as its internal ballistics. Most modern firearms (except muskets, shotguns, most tank guns, and some artillery pieces) and air guns (except some BB guns) have helical grooves called riflings machined into the bore wall. When shooting, a rifled bore imparts spin to the projectile about its longitudinal axis, which gyroscopically stabilizes the projectile's flight attitude and trajectory after its exit from the barrel (i.e. the external ballistics). Any gun without riflings in the bore is called a "smoothbore" gun. When a firearm
Gun barrel subjected to the greatest thermomechanical stress and therefore suffers wear the fastest. Throat erosion is often the main determining factor of a gun's barrel life. The muzzle is the front end of barrel from which the projectile will exit. Precise machining of the muzzle is crucial to accuracy, because it is the last point of contact between the barrel and the projectile. If inconsistent gaps exist between the muzzle and the projectile, escaping propellant gases may spread unevenly and deflect the projectile from its intended path (see transitional ballistics). The muzzle can also be threaded on the outside to allow