How the Army Is Upgrading Its Standard Rifle

​The soldier's standard weapon is getting a lot of improvements.​

A new U.S. Army video shows how today's standard infantry weapon, the M4 carbine, is being updated to perform better on the battlefield. The Army is gradually converting its entire inventory of M4s to the improved M4A1 standard.

The M4 carbine is the standard issue weapon for the U.S. Army. Introduced in the early 2000s, the rifle has performed well in Iraq and Afghanistan. In a 2006 report prepared for the Pentagon, 89 percent of soldiers polled said they were satisfied with the performance of the weapon, the highest rating for all Army small arms.

Even so, there is room for improvement. A weapon like the M4 designed for a wide variety of environments and operating conditions—from the Arctic wastes to the high, hot mountains of Afghanistan—has to incorporate some tradeoffs. A light weapon is easy carry on patrol, but that means a lighter barrel more prone to overheating in sustained firefights. A weapon that restricts the user to semiautomatic and three-round burst nixes fully automatic fire, but helps conserve ammunition on distant battlefields.

The new M4A1 standard addresses these issues and others. Where the original M4 was capable of semi-automatic and three-round burst fire, the M4A1 trades burst fire for fully automatic. The carbine is fitted with a heavier barrel that can better withstand prolonged, full automatic firing.

M4A1 carbine at the range.

Another improvement makes the rifle easier to use for lefties. Previously, left-handed shooters had to take their hand off the grip and trigger to safe or arm their weapons. The carbine now has an ambidextrous fire selector.

The new carbines undergo extensive checks at the refurbishment facility. They're also put under a laser engraver that not only crosses out the "BURST" wording on the side of the receiver and replaces it with "AUTO", it also adds an "A1" to the M4 designation.

While many of the parts on the refurbished guns are new, it's surprising how worn the weapons look. These are not the guns of garrison army, but of an army that for nearly a decade has fought two wars at the same time. That said, the lack of finish isn't an indication of their functionality. Almost all of the key parts of an M4A1 are made of aluminum and steel and would take many decades to wear to the point of unserviceability.