As adversaries continue to update their body armor, the Army is examining ways to upgrade its rifles to keep pace.
The service has been employing its standard-issue M4 carbine since the 1960s while steadily making improvements to the system over time. But now, the rifle's 5.56 mm round may not be able to penetrate enemies' newly developed body armor, officials said.
During a Senate Armed Services airland subcommittee hearing last year, Sen. Tom Cotton, R-Ark., noted that "everyone from Russia and China, to Hezbollah" and the Islamic State is employing advanced armor that "risks making the 5.56 round essentially obsolete."
However, the cartridge still has advantages when compared to the 7.62 mm round, which is also being considered as the caliber for a new rifle, Cotton said. Soldiers can carry twice as many, shoot with less recoil and shoot in quicker succession with more accuracy, he noted.
"The key is finding the right combination of weight, recoil, impulse, range and lethality," he said.
Thomas Spoehr, an analyst at the Heritage Foundation, a Washington D.C-based think tank, said the M4 rifle is often criticized for its lack of lethality at ranges greater than 300 meters and its tendency to jam when firing a large number of rounds. Soldiers often have to engage at ranges greater than 300 meters when operating in Afghanistan, he noted in an interview with National Defense.
Army Chief of Staff Gen. Mark Milley also marked this as a critically important area of concern in his testimony before the Senate Armed Services Committee last year.
He pointed out that purchasing body armor strong enough to counter the 5.62 mm round is affordable for adversaries. However, the Army would be able to replace the M4 "relatively quickly," he predicted.
But the service must also concentrate on the effectiveness of the bullet, and the Army has already begun developing a solution, he noted.
"The key on any of these things is not so much the rifle, it's the bullet--it's the ballistics of the bullet," he said. "Down at Fort Benning we've done some experiment and developmental work. ... We know we have developed a bullet that can penetrate these new plates."
Although the service has yet to formally announce its plans for new bullets, it did attempt to kick off a formal effort for an M4 replacement last year with the interim combat service rifle project, which was canceled in November.
But Spoehr pointed out that these are not the first conversations about an M4...