Will The PMAG Solve The Debate Over The M855A1?


As I’ve previously talked about the current divide between the Army and the Marines over the M855A1 has recently come to a head in Congress. The split over what specific cartridge to use back in 2010 has led to the current situation. However, with the recent adoption of Magpul’s PMAG the Marines and the Army may be moving closer to settling on a single 5.56 NATO cartridge to use.

Will The PMAG Solve the Problem?

Marines fire weapons at targets during a simulated attack with CS gas, also known as tear gas, during live-fire training as part of Exercise Koolendong 16 at Bradshaw Field Training Area, Northern Territory, Australia, Aug. 18, 2016. Marine Corps photo by Sgt. Sarah Anderson
Marines fire weapons at targets during a simulated attack with CS gas during live-fire training. Marine Corps photo by Sgt. Sarah Anderson

On December 19th, the Marine Corps Systems Command stated that they would authorize the use of the Gen 3 Windowed PMAG in black and medium coyote tan for use by all Marines. Magpul issued a statement on their Twitter account,

In light of the results from an enormous body of reliability and durability testing and 4 years of combat use, today it was announced that the PMAG 30 AR/M4 GEN M3 Window, in Black and Medium Coyote Tan (MCT), would be the official magazine of the entire United States Marine Corp.

However the decision to do this is because of the need to have a magazine that can reliably feed the M855A1 rounds. Some Marines found themselves deployed with access to only M855A1 rounds, and without magazines that would reliably feed them. The solution was to adopt the PMAG which had, in previous generations, been banned for use due to compatibility issues with the M27 IAR back in 2012. This reversal comes due to the ongoing testing showing that while the M855A1 meets the all of the requirements for a general purpose round it, however, was having feeding issues. When switching over to PMAG’s the issues were taken care of according to Chris Woodburn, deputy branch chief for the Marine Corps’ Maneuver Branch, saying,

In this case, it appears the stoppages that we were seeing were primarily magazine-related in terms of how the magazine was feeding the round into the weapon

But The Magazines Were Not The Only Problem With The M855A1

However there are still some ongoing issues with the M855A1 that leaves some concerned about the round. In his interview with Military.com Woodburn explained that, 

“Where it still appears that we still have an issue with it is it appears to degrade the durability,” Woodburn said. “Durability is mean rounds between essential function failures, so you are talking bolt-part failures, barrel failures and the like.

“It is a hotter round and we think, that may be contributing to it, but we won’t know for sure until the testing is complete,” he said.

Marines set up an M777 howitzer for a fire mission during a battle drill at Fire Base Burt, Calif., Oct. 1, 2016. The Marines are assigned to 1st Battalion, 11th Marine Regiment. Marine Corps photo by Staff Sgt. Artur Shvartsberg
Marines set up an M777 howitzer for a fire mission during a battle drill Marine Corps photo by Staff Sgt. Artur Shvartsberg

I’ve talked to a few knowledgeable friends about this issue and one expressed similar concerns, the M855A1 is indeed a hotter loading of the 5.56 NATO. At around 63,000 PSI it is approaching proof loadings used to test the integrity of the barrel and breech. While the 5.56 NATO is supposed to be a “hotter” round, frequently shooting over pressure ammo is going to dramatically decrease the service life, and accuracy of the Army’s firearms. Some sources say that the M855A1 cuts barrel life in half. Furthermore the M855A1’s exposed penetrator has the potential to wear out feed ramps faster unless the feed ramps are changed to a harder material. But, it seems that no changes to the rifles’ specifications have been made to address any of these issues. Finally with a 5.5 MOA standard compared to the MK 318 SOST’s 2 MOA standard one has to wonder why the “new” round is being held to a lower standard than the one that it’s possibly going to replace in Marine’s rifles.

Finally the “green issue”. As many have already said I personally think that any attempt to make a round more “environmentally friendly” is a waste of time. If a round shows better performance and just so happens to be “green”, that’s fine, however with the M855A1 trying to be green it seems like a decision to put the cart before the horse.

While Col. Michael Manning, program manager for the Marine Corps Infantry Weapon Systems, stated that he would like to see both the Marines and the Army standardize around a single loading there are still some legitimate concerns that need to be addressed, especially if the switch to the PMAG indicates that the Marines are open to adopting the M855A1 cartridge.

Meanwhile Magpul has released a rather funny little video talking about their new MCT magazines.

What are your thoughts on this issue of the M855A1 and the MK 318? Are you excited to see the Marines approve the PMAG? Sound off in the comments below.