Why PMAGs Are Better Than Aluminum USGI Mags

This subject is currently at some higher levels and I put this together to give some end user perspective. I’ve been involved with PMAGs since almost the beginning and I have not found another magazine which meets my requirements or that I trust unequivocally, like the PMAG. The below is an attempt to describe why they are better, in a military environment and specifically with M855A1

SUBJECT: Increasing reliability of the M4/M16 Family of Weapons (FOW) when using M855A1 5.56mm ammunition through the use of Magpul Industries Polymer Magazine (PMAG) GEN M3

1) Purpose: Provide first hand experience and benefits of issuing the Magpul PMAG compared to currently issued aluminum magazines

2) Summary: M4/M16 magazines rely on correct feed lip geometry (angle) to feed cartridges reliably. Reliability is reduced with M885A1 ammunition in all generations of aluminum magazines, to include the latest government issued tan or blue follower aluminum magazines, based on bullet shape and exposed penetrator tip. The Magpul PMAG is the only magazine which maintains correct geometry and has been shown to increase reliability with M855A1. Recent Marine Corps tests confirm this. Most telling is that the PMAG is the #1 piece of equipment that Soldiers will spend their own money on prior to deploying, based on its increased reliability.

3) Background: I have been an infantryman for 23 years. I enlisted as an 11B Infantryman in 1994 and was commissioned as an Infantry officer in 1997. I have multiple deployments to Iraq and Afghanistan and have served in mostly light infantry units to include the 10th Mountain Division, 101st Airborne Division, and currently serve as a light infantry battalion commander. In 2009 I wrote a white paper titled “Increasing small arms lethality in Afghanistan: Taking back the Infantry half-kilometer” (available online) as part of my School of Advanced Military Studies (SAMS) research requirement. I discussed several current shortfalls with equipment and training, as well as ways to increase the lethality of our Soldiers. One area discussed was the reliability of the M4/M16 family of weapons.

4) Discussion: The M4/M16 FOW is the best carbine/rifle system in the world and I have used most rifles in use by our allies. A quick look at most any tier 1 unit from any of our allies will show they prefer and use the M4 in lieu of their own standard issue rifle. Reliability of the system is primarily dependent on two things: Adequate lubrication and good, clean magazines. The former is mostly a training issue, but the latter has been a constant source of frustration for end users for over 50 years.

5) The magazine: The purpose of the magazine is to hold the 5.56mm cartridges and allow positive feeding into the chamber of the barrel. To accomplish this, the feed lips must be at a specific angle and at a specific spacing apart to retain the cartridges in the magazine while under the tension of the spring and present the correct angle of the cartridge to the chamber as the bolt pushes the cartridge forward out of the magazine and into the chamber. Current issued aluminum magazines feed lips are easily deformed through normal handling, training, and operations and may alter these critical dimensions. Even slight deformation will result in malfunctions and these deformations are normally not detectable by most Soldiers until they have a malfunction and closely inspect the magazine. Further, current issue M855A1 (replaced M855 “green tip” in 2012) requires an even more precise feeding angle based on the exposed hardened penetrator tip. If the angle is low, the bullet tip will stop on the front edge of the receiver/feed ramp, causing a malfunction. I have personally witnessed failures to feed with this ammunition and new tan follower aluminum magazines, both in training and while deployed. The problem persists with the very latest blue follower aluminum magazine, which was created to address the feeding issues with M855A1. The problem is only reliably remedied with the use of PMAGs.

6) The PMAG: In 2007 Magpul Industries released a polymer magazine known as the PMAG. I personally procured several magazines and I was impressed with the design and benefits of the magazine. At the time, I was an Observer/Controller at the Army’s Joint Readiness Training Center, Live Fire Division. The Live Fire Division procured over 600 PMAGs for testing under various adverse conditions. Testing was conducted over a six-month period and included every type of live fire munition to include blanks, short-range training ammunition (SRTA), and Ultimate Training Munitions (UTM). Feedback was obtained from various ranks and experience levels, various branches to include Army, Navy and Marines, and used in the M4, M16 and M249 Squad Automatic Weapon. The magazines were dropped, thrown, run over, covered in sand, mud and water and exposed to typical chemicals such as DEET, weapons lubricants, gasoline, diesel fuel and motor oil. The unanimous feedback from users was that the magazine was better than the aluminum magazine, reliability was increased, and Soldiers and Marines wanted them for their deployment. The latest version of the PMAG is the GEN M3, which was introduced in 2012 and incorporates even stronger materials and a dot matrix marking system to keep track of magazines. The recently approved PMAG for the Marine Corps is the PMAG GEN M3 MCT (Medium Coyote Tan) with window.

7) Benefits of the PMAG:

a) The proprietary polymer construction of the PMAG is consistent and reliable. The feed lips maintain a constant geometry when loaded or unloaded and do not fatigue, expand, or deform. They can be dropped fully loaded directly on the feed lips with no damage or reliability issues and pass all current Army and NATO rough handling standards and temperature requirements for operation between -60F to 180F. If the magazines become damaged to the point of affecting reliability (extremely uncommon), the damage is easily visible to the Soldier/Marine and the magazine can be discarded and replaced. The magazine also fits all current magazine pouches and bandoleers.

b) The secondary benefit in the design and one that I don’t think is highlighted enough is the ability to quickly disassemble and clean the magazine. Magazines used by Soldiers/Marines with get dirt and sand inside them. This affects reliability and the magazines and ammunition should be cleaned routinely while deployed or following training. The PMAG can be taken apart in seconds by pushing a tab on the bottom with the tip of your finger. It is perfectly sized so that it cannot be inadvertently depressed. It allows the user to wipe down the components of the magazine and run a rag through the body. The aluminum magazine is much harder to disassemble and often results in damage to the magazine on one or more of the four small aluminum tabs, which keep the magazine together. If any of the tabs are damaged, the magazine will come apart, normally at the most inopportune time. Many Soldiers/Marines will tape the bottom of their magazine to prevent this from occurring, but that further hinders routine cleaning.

c) The version of the PMAG GEN M3 with a narrow clear window slot allows Soldiers/Marines to quickly glance at the magazine and determine if the magazine is fully loaded and get an accurate estimate of remaining rounds. This is impossible with aluminum magazines and requires removing the magazine from the weapon and judging by weight to determine remaining ammunition available.

d) It is a common practice to download the number of cartridges in an aluminum magazine from 30 to 28 to allow loading a magazine with the bolt carrier forward. The aluminum magazine design does not allow much compression when fully loaded and will often result in a magazine not being fully seated in the weapon and the magazine falling out while moving or after firing the first round. The PMAG allows compression when fully loaded with 30 rounds and easy seating of the magazine with the bolt carrier forward, reducing the likelihood of the magazine not being fully seated.

e) Further benefits include the ability to use the magazine during training or for emergencies with the M249 SAW. The M249 SAW has a provision to take magazines instead of belts in an emergency, allowing members of the squad to supply ammunition for suppressive fire. Aluminum magazines are notorious for causing malfunctions when used in the M249. The PMAG is the only magazine that reliably feeds in the M249.

f) Finally, the optimized feed lip geometry allows the magazine to be effectively used as a monopod support when firing. In practice, the Soldier/Marine rests the bottom of the magazine on the ground or other support, which aids in keeping the weapon still and allows greater accuracy. With aluminum magazines and the greater potential for misalignment of the cartridge to the chamber, this practice often leads to a malfunction.


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