A U.S. Marine at the range with an M4 carbine in 2013.

It looks like the M16 rifle, which has served the U.S. Armed Forces since Vietnam, is on its way to the military history museum. The Marine Corps is looking to retire the M16 platform, and possibly the M40 family of sniper rifles as well.

According to this story from the Marine Corps Times, Marine leaders have made a recommendation to ditch the M16A4 in favor of making the M4 carbine the new universal infantryman weapon for the Corps. If approved, the shift will relegated the M16 to a support role, following a similar shift in the Army.

“The proposal to replace the M16A4 with the M4 within infantry battalions is currently under consideration at Headquarters Marine Corps,” according to a jointly written response from the commands provided by Maj. Anton Semelroth, a Marine spokesman in Quantico, Virginia.

The change would be in response to reports from infantrymen who say the M16A4 is too long and unwieldy for the close-quarters combat typically faced in Iraq or in vehicle-based operations in Afghanistan, in which the M4 carbine excels. The M4 also saves weight and includes a collapsible butt stock, which is important for Marines wearing body armor in tight spaces.

For instance, during Operation Phantom Fury in 2004, Marines fought to take control of Fallujah, Iraq from Iraqi insurgents in extreme close-quarters combat. They had to resort to “short-stocking” their M16s in order to come around corners and get on target in small rooms. That means putting the rifle stock over the shoulder and canting it at 45 degrees to use the optics—not a great shooting position.

“I would have to say my gut reaction is it’s the right choice and will do a lot of good for the guys in the infantry,” said Sgt. Nathan West. “The M4 is a great weapons system that has done everything I have ever asked of it.”

The evolution of the M16 rifle, from top: M16A1, M16A2, M4, M16A4.

Once approved by Commandant Gen. Joseph Dunford, the switch could occur as soon as unit armories can issue weapons, because the 17,000 M4s needed to outfit infantrymen with currently issued M16s are already in inventory.

The M4 has a short, 14.5-inch barrel with an overall length about 10 inches shorter than the M16A4. It weighs in at just over six pounds, a pound lighter than the rifle. The shorter barrel does sacrifice some muzzle velocity, meaning a slightly shorter effective range. But in close-quarters battle, that is rarely a factor, and each Marine fire team already has an M27 Infantry Automatic Rifle, which in semi-auto doubles as a designated marksman’s rifle. That role will no longer be filled by the Squad Advanced Marksman Rifle, a match-grade M16 with a scope.

The Corps may also be looking to retire another Vietnam-era service weapon, the M40 family of bolt-action rifles. Since the 1960s, the Remington 700-based 7.62 NATO sniper rifle has seen changes to its chassis, optics and barrel, but its effective range was never extended beyond 1,000 yards due to the practical limitations of the 7.62×51 cartridge, according to

“The Marine Corps is looking to field a new sniper rifle, but has yet to identify what type and caliber, according to a Marine spokesman.

The Mk.21 Precision Sniper Rifle, also known as the Remington Modular Sniper Rifle, may replace the Marine Corps’ M40.

‘We are looking at a number of available options, to include the Mk.21 Precision Sniper Rifle,” stated Maj. Anton Semelroth in an email. ‘The Marine Corps continues to evaluate the need for improved capablilities for our snipers and to consider solutions being pursued by the Army, other services and (Special Operations Command).'”

The Mk.21, also know as Remington’s Modular Sniper Rifle, can swap among four calibers (.338 Lapua, .338 Norma Magnum, .300 Winchester Magnum, and 7.62×51) and would nearly double the practical range for Marine snipers, if that’s the way the Corps decides to go. Another contender is yet another Remington 700-based sniper rifle used by the Army, the M2010 chambered in .300 Winchester Magnum. The M201 is currently replacing the Army’s M24 sniper rifles.