The future of the Army’s 5.56mm rifle caliber is being seriously questioned and there may be a replacement as early as 2020.
The Army is testing many different calibers with the potential to replace the 5.56mm and M4 carbine with a heavier-hitting round. A wide variety of ammo is being looked at, including 6.5 Creedmoor, .260 Remington and .264 USA, along with some experimental designs. All these calibers span the gap between the lighter 5.56mm and 7.62mm (which is more commonly used in light and medium machine guns).
The project looks to provide a more effective caliber at longer ranges, but still allowing a soldier to carry the same amount of ammo as the 5.56mm by maintaining similar weight loads.
Military leaders and the soldiers on the ground have long been critical of the 5.56mm round, saying it doesn’t provide the range and firepower needed on the battlefield. Combat After Action Reports point out that in may cases, U.S. war fighters are outmatched by their foes, who often carry larger caliber rifles, putting U.S. troops at a disadvantaged in range, accuracy and firepower.
Battlefields such as Afghanistan often see troops in contact at fairly long ranges with insurgents, who in many cases are able to put down longer range fire. One important case study produced by Major Thomas Ehrhart looked closely at this problem. The report is titled “Increasing Small Arms Lethality in Afghanistan: Taking back the Infantry Half-Kilometer,” and it highlights that many of the direct fire engagements were at more than 300 meters and the lethality of 5.56mm was reduced at longer ranges.
The two recommendations from the report were to produce a superior 5.56mm round or look at more effective calibers for longer ranges. There is also an increasing use by opponents of body armor. With ballistic plates and soft body armor on opponents there is a push to have a heavier hitting rifle round to defeat these defences. Also; cases of jamming and design flaws continue with the M4, providing momentum to move onto a new rifle and caliber.
Though many combat veterans have expressed that the M4 5.56mm rifle has been adequate the rifles are starting to reach their end of life-cycle use from continuous wear and tear. Many experts see that the time may be right to field a newer caliber and rifle to address the problem.
The debate in rifle calibers for U.S. forces is not a new topic and has been ongoing for decades. There was a shift from heavier calibers, such as .30-06 to .30 caliber in World War 2, and eventually a complete transition from the 7.62mm M-14 rifle to the M-16 5.56mm during the Vietnam conflict. During each stage there have been critics of these changes.
Research and study on a replacement caliber has been ongoing in Fort Benning, Georgia, home of the infantry, since 2014. Army sources expect the report to be concluded in the next three months to provide recommendations.
It appears that the Army may soon phase out 5.56mm as its standard service rifle round.