Army Kills M4 Replacement Program

The Army Kills its Plan to Replace the M4 Carbine Rifle

The hunt for a more powerful rifle is over. But what's next?

By Kyle Mizokami

The Army's program to replace the M4 carbine with a larger, harder-hitting rifle is dead, canceled after just under two months. But now that the Interim Combat Service Rifle is dead, what's next?

The Interim Combat Service Rifle was proposed as a means of countering the new generation of cheap, highly effective body armors likely to be worn by America's enemies . Countries such as Russia are now issuing body armors that can allegedly stop a .30-06 armor piercing bullet. Experts inside and outside the Army believed that the Army's current issue 5.56-millimeter bullet would not be able to penetrate new armor, and that a larger, heavier bullet that transfers more energy to the target is necessary. Like everything else in the domain of military weapons, it's an arms race between measure and countermeasure.


6.5mm Carbine Weapon, currently under development.
Textron photo.

Critics of the ICSR program felt that the Army was jumping the gun and that the threat did not necessitate an entirely new rifle. Plus, using a new rifle in the larger 7.62-millimeter caliber would be heavier, require heavier ammunition, and hold less ammunition than a M4 carbine—three less-than-desirable attributes for infantrymen. The Army had also already said the technology behind its new XM1158 ADVAP armor-piercing round could be adapted to 5.56-millimeter caliber, which made a new rifle in a new caliber pointless.

What happened to cancel the ICSR? The blog Soldier Systems Daily claims that Army Chief of Staff Mark Milley had a "squirrel!" moment watching Textron's new LSAT rifle concept in action. LSAT uses new "cased telescope" technology in which a bullet is totally enclosed in a polymer casing and surrounded by gunpowder. This allows the LSAT round to be shorter and weigh less than traditional bullets with brass casings. LSAT is offered in a new 6.5-millimeter round but is also available in more traditional 5.56 and 7.62-millimeter models. LSAT is not part of the ICSR competition.

We don't know if the LSAT will eventually become standard U.S. Army issue, but we do know that the decision to start the ICSR program was hasty and in all likelihood unnecessary. While the Army should adopt a new weapon and caliber if absolutely necessary, that doesn't seem to be the case—yet.