Wednesday, February 10, 2010

Praxis: M-16/M-4 Magazines

My sincere thanks to Pete at WRSA for drawing my attention to this.

I will have a longer post dealing with the larger issues raised in this monograph, but for now let me draw your attention to this snippet below on magazines. I have been slowly going over my cached mags, replacing black followers with green and swapping GI springs for Wolff. As I do, I inspect the mag bodies for problems, throwing any with dings, cracks or bulges into the trash along with the black followers. If I had the money, I would buy all P-Mags for the girls' M-4geries, but I don't, so I continue to upgrade the mags I have as I can afford it. Although, Midway (if I recall correctly) recently ran a sale on Type One's for $10 each if you bought ten. That's hard to beat.

Anyway, here is MAJ Ehrhart on the subject of magazines.


Standard USGI-issue M-16/M-4 magazine.

The magazine is an important part of the rifle. When originally designed by Eugene Stoner, the magazine was meant to be a lightweight, disposable item. Due to this concept, the magazine was made from aluminum and not designed to be durable. Soldiers soon learned that the magazine was not disposable and that care was required to keep the weapon reliable.

There are several things that soldiers can do to ensure their magazines work. The most important thing to do is to keep them clean. Just as sand can find its way into the rifle, it will find its way into the magazines. Magazines should frequently be disassembled and brushed clean. Pulling a cleaning rag through the body several times is adequate. Inspect the back of the feed lips to ensure they are not cracked and the lips have not spread apart. Load about 15 cartridges into the magazine and while holding it in one hand, smack the base of the magazine with the other. If several rounds pop out, either the feed lips are spread and/or the magazine has a weak spring. The entire magazine should be discarded. Soldiers can identify potential problems in magazines by numbering each magazine with a paint marker and noting any malfunctions caused when the magazine is used in the weapon.

MagPul P-Mag Type One magazines, with inspection window.

Several upgrades are available to increase the reliability of the issued magazines. A company called Magpul makes the best upgrades the author has used. Their original product consisted of a slip-on rubber ring for the bottom of the magazine. It made it easier to grasp your magazines from your ammunition pouches but also protected the delicate floor plate tabs, which have a tendency to break after extended use. They also designed a new, anti-tilt follower that greatly increases feeding reliability of the standard issue magazine. In 2007, the company came out with their own version of a magazine for the M16/M4 known as the PMAG. Constructed of resilient polymer, the magazine is nearly indestructible. (Figure 8) When the polymer cracks or breaks, it is easily recognizable, unlike with the standard issue magazines. These magazines represent the cutting edge of technology for making the rifle more reliable. Recently, the PMAG was assigned a national stock number, so units can now order these magazines through the supply system. 87 All combat arms units should consider replacing their standard issue magazines with the much more reliable PMAG.

P-Mag Type II, Solid Body.

Magpul PMAG NSN's are 1005015765159 for a black magazine and 1005015765164 for a black magazine with a narrow translucent window on both sides of the magazine with witness marks for 5, 15, and 25 rounds. -- Increasing Small Arms Lethality in Afghanistan: Taking Back the Infantry Half-Kilometer, MAJ Thomas P. Ehrhart, USA, pp. 43-44.


dinsdale said...

He's a acquaintance, as we both live in Texas and are involved in firearms, but I have no fiscal interest in saying that I really like Virgil Tripp's 42 and 52 round Cobra Mags for AR/M purpose. He lives in Alpine, I live near Arsetown in the "Central Highlands", and we aren't brother in laws...BUT, They work, they feed, and they're built like a proverbial brick sh*thouse, with proper springs and followers for the task and the extension is a nice sturdy bit of machining.

That said, for general purposes I find 20 round magazines handiest and purchase good ones of various brands and/or swap in good springs and followers to otherwise good housings.

in defiance said...

DSG Arms
has standard issue mags with green followers for $6.95 and Pmags for $11.21.

Pericles said...

The only issue I have with PMAGs is in using the standard spoons and stripper clips to load them - it ends up being one round at a time. Even if you use a PMAG loader, you feed the rounds into the loader one round at a time.

Newbius said...


IMHO, the money quote in the attached article is the following:
"The fact is that in its search for the suppressive fire capability of automatic fire, the U.S. infantry weapon has devolved from the World War I rifle capable of conducting lethal fire out to 1,200 yards, to the current weapon that can hit a target out to 300 meters, but probably will not kill it. Not only is the current U.S. infantrymen less equipped to kill his enemy than his World War I predecessor, he is carrying far more weight than him."

I find it very interesting that this white paper acknowledges the realities of the "300-meter war" chapter of Absolved. Nice work.


Anonymous said... has c-product mags with black no-tilt followers for $7.95 ea.

You order @200 worth free shipping.

also have CMI M14 mags (current GI contract for $20.50 (if memory serves)


gandalf23 said...

Magpul also makes 20 round magazines, for those that want smaller sized mags.

DSG Arms had black 30 round Magpuls with window 10/$100 recently, but it looks like they are done with that price and are $11.21 per mag now. Still a great deal. Elsewhere the mags go for $20 each.

I have swapped out most of the green followers in my magazines for magpul bright orange no tilt followers. I really like the bright orange for quick looks check that the chamber is clear. They also make followers in grey (and black, I think) for people who do not want bright followers.

C-Products also has a similar anti-tilt follower that is available in multiple colors.

Loren said...

Pericles, you might take a look at Camega loaders. They have ones that will loose loose ammo, but also one that will load from stripper clips. They should work with Pmags.

Stephen Boyd said...

In my opinion, Pmags are the best quality and the cheapest price.
Makes the choice pretty easy.

Anonymous said...

Aren't you missing the point? It's not there is now a better magazine for the 5.56, but that the 5.56 is not an appropriate caliber for an MBR. I would suggest that instead of spending (wasting?) money on new mags, followers and springs, you put that money towards an MBR that has a 600+ m range, whether its a 308, the newer 6.5 or 6.8 mm rounds, or whatever floats your boat.

Pat H said...

Magazines are one of the critical and sometimes weak link in the serviceability of the AR rifle.

An AR chambered in the outstanding 6.5 Grendel was hamstrung with problematic magazines for quite a while.

The current C Products magazines for that caliber, the only magazines for it at this point, have cured the problems with anti-tilt followers and stainless steel bodies that resist deformation better than aluminum, though at a weight penalty certainly.

Still, the 6.5 Grendel and the slightly less powerful 6.8 SPC extend the AR-15 rifle well into the 7.62NATO operational zone, offering at least 200 meters greater combat radius than the 5.56NATO, making them worth any teething problems.

jon said...

this is a pretty convincing whitepaper. it's got me pricing out the cost of maintaining a dual-purpose lower for 5.56/6.8spc. just the other day i was reading about the glories of .260 remington; this dovetails nicely with what competition shooters try to squeeze out of the two-sixty (but they don't care about how hard it hits the paper). the attention to detail is very good. i feel like i knew all this, but, now i KNOW it.

sounds like open season on 7mm rifle designs. i like that. maybe someone will make an M14 knockoff that delivers it. that'd be a beautiful thing.

just FYI the section on optics mentions the M68CCO; i don't know if this is common knowledge yet, but this is just the aimpoint compM4. same thing, military designation. you ought not pay more than $650 for one, but i hear tell they're the bees knees.

Dakota said...

I do not care for the Magpul mags. They do not fit in my pouches because of the large bottom piece. They are otherwise OK.
I disassemble my mags usually on a yearly basis clean the dust off if any and use a rag that I keep in a plastic bag with a small amount of preservative oil/lube. I go over the spring and reassemble. The rag is not wet and does not leave a liquid film on the parts. I actually like the 20 rounders better than 30s the weapon is better balanced IMO. I use heavy OD duct tape on the bottom to aid pulling out of pouches and spend extra money on other items I need worse than fancy end caps.

Landau Nunder said...

On the subject of 'increasing small arms lethality" - and I am all in favor of that! - someone might want to try moving rifle calibers up to 7.62 / 308 for a minimum. Then the men can pick a target, engage it from a proper distance and terminate it with no 'spray and pray'.

Anonymous said...

Pericles, I tried using the standard spoon/stripper clips with my 20 round pmags and had no problem.

Michael Gilson said...

Anarchangel had a pretty good overview of M-16 mags a year and a half ago. You can find it at

As for 5.56 long range lethality, IIRC the A2 and beyond series over stabilize ball ammo - the 1 in 7 twist is to stabilize the longer tracer rounds. If so perhaps going to a slower twist upper (1 in 9?) or a longer heavier ball round (75 grains?) would help.

theotherryan said...

I have never really had significant issues with AR/M4 mags. Occasionally an older GI mag comes along with either bad feed lips (you can tell when you see it and they don't want to go into the mag well) or a weak spring. If the spring is the issue get a new spring, they are affordable. Mags are at best semi disposable and do wear out.

PMAGs are nice. I have a few of them and if you take the time to shop around they don't cost much more than a buck over generic GI type mags anyway. Future AR mags I buy will likely by PMAGs.