Future military rifles: alternative small arms technologies 

For decades, soldiers all over the world have relied on rifles that fire NATO standard 5.56mm or 7.62mm ammunition. Recent conflicts, however, have highlighted inherent limitations and spurred the development of alternatives that can meet emerging requirements. Grant Turnbull finds out what’s next in small arms technology.

Live fire training in Afghanistan. Image: US Army


These shortfalls predominantly centre around the NATO 5.56mm bullet, standardised across the alliance in the 1980s and now fired by most individual service weapons outside of Russia and China. This is a high-velocity bullet, giving pinpoint accuracy for soldiers over long range and, at just 4g, it can be carried in significant numbers by squads, meaning more weight of firepower during engagements.

But it is no magic bullet. For special forces units, the 5.56mm is not ideally suited to close-quarter engagements such as inside buildings or tunnels. For regular units, the projectiles lacks effective range for longer distance engagements. The high velocity and low mass of the 5.56mm projectile means it lacks 'stopping power' - a colloquial term for quickly neutralising a target - and in confined spaces can also cause increased collateral damage as it passes through walls or other structures.

Rifle requirements for close quarters


One key trend we observed at the arms show was the growing move towards an alternative bullet, known as .300 Blackout (BLK), for special operations missions. Compared to the 5.56mm, this larger 7.62x35mm bullet offers significantly more stopping power for close-quarter engagements, owing to its larger mass and lower velocity.


Rifles on display at the EnforceTac exhibition.

Several rifle manufacturers, including SIG Sauer, FN Herstal and Steyr Arms, demonstrated 5.56mm rifles that could be converted to fire this ammunition. Steyr Arms highlighted its classic AUG in a new configuration optimised for .300 BLK, with a company spokesperson noting that the ammunition’s popularity was getting “bigger and bigger”, particularly amongst special forces units.



FN Herstal recently released a new variant of its SCAR-SC that can fire the larger .300 BLK ammunition. Image: FN Herstal


Klement told us that he still sees demand for 5.56mm, particularly owing to its superior aeroballistic performance, and thus better accuracy, over long ranges. An FN Herstal spokesperson also noted that the company still sees current NATO calibres remaining in widespread service in most alliance countries for many years to come. Many countries, including France and Germany, are currently introducing new rifles from companies such as Heckler & Koch that are chambered for 5.56mm and will likely be in service for another 20-25 years.

Austrian company Steyr Arms revealed details of its new AUG configured to fire .300 BLK at Enforce Tac. Image: Grant Turnbull

The US looks beyond 5.56mm




As part of its Small Arms Ammunition Configuration (SAAC) study completed in 2017, the US Army decided to pursue an ‘intermediate’ ammunition measuring 6.8mm. “That was the right calibre to go to, especially considering I wasn't going to do a commercial off the shelf cartridge,” explained Easlick. “6.8mm made the most sense.”

Special forces soldiers are increasingly looking at alternative ammunition types, particularly for close-quarter engagements. Image: US DoD


While the decades-old NATO rounds of 5.56mm and 7.62mm will still be around for decades to come, it is clear that there is now a growing demand to replace them for both close-quarter and long-range engagements. The US Army’s planned replacement for the M4 Carbine and the introduction of the 6.8mm - which limits interoperability with NATO allies - could be a catalyst for a new era of standardisation that eventually phases out the 5.56mm.

An example of .300 BLK ammunition (first three rounds on the left), compared with 5.56mm and 7.62x39mm ammunition on the right.