The senators' letter may be misinformed, since soldiers have used PMAGs extensively in some of the heaviest gunfights of the war in Afghanistan.
Sen. Joni Ernst, a Republican from Iowa, a combat veteran and member of the Senate Armed Services Committee, on Friday led Sens. Tom Cotton, a Republican from Arkansas; Jim Inhofe, a Republican from Oklahoma; Johnny Isakson, a Republican from Georgia; and David Perdue, a Republican from Georgia, in sending a letter to Army Chief of Staff Gen. Mark Milley questioning "why polymer ammunition magazines for United States Army rifles are not authorized for use in combat or in training."
The letter stems from the Marine Corps' recent decision to authorize PMAGs for its M27 Infantry Automatic Rifle after the weapon experienced reliability problems in an Army test with M855A1 ammunition. The Corps also authorized PMAGs for its M16A4s and M4 carbines.
"Reports state that the polymer magazines approved for use by the Marine Corps had zero magazine-related stoppages through all of the tests carried out by the Marine Corps when combined with any ammunition tested. Additionally, reports state they also reduce damage to the chamber face and feed ramps when using M855A1 ammunition. As our national debt approaches $20 [trillion], ensuring the longevity of these rifles is important," the letter states.
The letter also states, "The Army and Marine Corps simultaneously issued orders stating that polymer magazines were not authorized for use in 2012."
Army officials from the TACOM Life Cycle Management Command did issue a message in April 2012, declaring that only government-issued aluminum magazines were authorized for use in the M4 and M16 rifles.
TACOM officials released the message to address reports of Army units using "unauthorized" commercial, polymer magazines such as the popular PMAG, introduced by Magpul Industries Corp. in 2007. The decision left combat troops puzzled, since the PMAG has demonstrated its extreme reliability in combat and has an Army-approved national stock number, which allows units to order them through the Army supply system.
Army officials, however, acknowledged in a June 6, 2012, statement that TACOM's message was poorly written and not intended as a directive on the use of PMAGs. Matthew Bourke, an Army spokesman at the Pentagon responding to questions from Mililtary.com at the time, said the message should have included guidance that the final decision rests with commanders in the field.
"At best, the message is incomplete; at worst, the message allows soldiers to jump to the wrong conclusions," Bourke said. "Maintenance Information Messages [from TACOM] are permissive. They are not an order. They are not a directive. All content and direction in those messages are optional for the recipient."
Military.com reached out to the Army for comment but did not receive a response by press time.
Meanwhile, TACOM announced in July that it was introducing a new M4 Enhanced Performance Magazine.
The new magazine will feature a tan body and blue follower and will be engineered to address feeding issues with M855A1 ammunition.
The Army first started to improve M4 magazines in 2008 after reliability tests found that the original follower caused many of the weapon's feeding malfunctions during the test.
PMAGs have developed a word-of-mouth reputation for being extremely reliable as well as durable. Special operations units such as Army's 75th Ranger Regiment issue PMAGs, as do many infantry units before war-zone deployments.
Soldiers from B Troop, 3rd Squadron, 61st Cavalry Regiment, had been issued PMAGs before deploying to Afghanistan in 2009. On Oct. 3 of that year, they fought off a bold enemy attack on Combat Outpost Keating that lasted for more than six hours and left eight Americans dead.
Some soldiers reported firing up to 40 PMAGs from their M4s without a single stoppage.
-- Matthew Cox can be reached at firstname.lastname@example.org.