AR Magazines, Buying The Right One, is There Really a Difference?

YouTube personality, Graham Baates, takes an analytical look at some measurable performance differences in standard AR magazines. If you find this article useful, you should read AmmoLand’s related articles Best AR-15 Magazine For Your Rifle ~ Review.

So Many AR 15 Magazines
So Many AR 15 Magazines

USA – -( What would a trip to the range or idle chat at the local gun store be without talking about the best magazine for your AR-15?

Name brands get tossed around worse than a Ford vs. Chevy argument, almost with the mysterious faith of the Glock vs. 1911 debate.  During the Obama years, it seemed like there was a new manufacturer every month.

Times were easy then, everyone was afraid that fresh 30-rounder they saw on the shelf might be the last mag they’d ever see on a shelf and we gobbled them up.  Now we all have dozens.  Some of AR magazines work, others not so well.  One AR rifle magazine that seems to work in one rifle doesn’t so work so well in another.  I decided to take a look at the why without worrying about the springs or followers which are easily replaced.

While serving in the Army, one of the significant concerns were the feed lips on our aluminum magazines.  Over-insertion, dropping them, shoving into a ruck or pouch, and even just time seemed to change the angle of the feed lips, and thereby the way rounds would strip.  The now-lost art involved using a stripper-clip guide to bend them back into place carefully.

Who’s AR Magazines?

Author's original "Mag-Pull" Magazine ca. 2004
Author’s original Army issue “Mag-Pull” Magazine ca. 2004

Now we’re in the age of polymers.  Just as we have come to accept polymer guns, polymer gun magazines are widely used.  What are the elements of the magic magazine have yet to be determined?  Why do some AR magazines work and others not?  I decided to take a look at dimensions and found some interesting (that’s relative) data.  Before we dive into the numbers, a few disclaimers are in order.  1.  My mag sample size was one(1pc ea).  2.  The magazines are of various ages.  3.  The calipers used were inexpensive but returned to zero after each measurement.  4.  Alphabetically brands tested include:

  • American Tactical Imports
  • C-Products
  • CAA
  • D & H
  • Daniel Defense
  • ETS
  • Okay Industries (pre-2004 government contract)
  • Okay Industries (2016 civilian market production)
  • H&K
  • Lancer
  • Master Molder 20-round
  • Mission First Tactical
  • NHMTG (government contract)
  • MagPul PMAG Gen 1
  • MagPul PMAG Gen 2 MOE
  • MagPul PMAG Gen 3
  • ProMag 40-round
  • TorkMag 35-round
  • Troy Industries

The video explanation and demonstration of the entire test can be seen below.

AR Magazines by the Numbers

The first measurements made were in the mag catch area.  I argue that these measures can influence the seated height and angle of the magazine, depending on your magazine catch.  One would expect that these numbers would all be similar, but they weren’t.  I can’t say which is best for your rifle, and in fact, they may all work, but it was an interesting finding.

AR Magazine Catch Height Measurement Chart. They are all somewhat similar except for ATI
AR Magazine Catch Height Measurement Chart. They are all somewhat similar except for ATI.


AR Magazine Mag Catch Width Measurement Chart: Width was less consistent. Does it not matter or is this how a magazine ends up askew in the well?
AR Magazine Mag Catch Width Measurement Chart: Width was less consistent. Does it not matter or is this how a magazine ends up askew in the well?
AR Magazine Mag Catch Depth Measurement Chart: The depth of the magazine catch can determine how firmly the mag is held prior to any adjustments on the rifle. Note the metal magazines have no bottom.
AR Magazine Mag Catch Depth Measurement Chart: The depth of the magazine catch can determine how firmly the mag is held before any adjustments on the rifle. Note the metal magazines have no bottom.

With the statics out of the way, I wanted to know how much these AR rifle magazines flexed when loaded.  As mentioned earlier feed-lip width can influence a lot, so what happens to that measurement between empty and 50% load?  What about 24 hours later, 48 hours later, and one week later?  Can we store AR magazine loaded without effecting performance? This is where differences began to show.  As a precursor, I measured feed-lip width before loading and immediately after a 50% load.  Some of the changes were unexpected.

AR Magazine Mag Feed Lip Width Change Chart
AR Magazine Mag Feed Lip Width Change Chart: Some lips contracted indicating that the body itself may have swollen.
AR Magazines feed lip Chart
A busy chart, but demonstrates the swell and contraction of AR Magazine feed lips. How did your brand do?
G B Guns
G B Guns

So what Magzine won?  That depends on what you’re looking for.  From this simple experiment, it appears that Mission First Tactical, Daniel Defense, 3rd Generation PMAG, and American Tactical are sure bets for maintaining geometry when stored loaded with ammo.  All of these magazines have run well in my rifles except for the Master Molder and Daniel Defense.

Once again this is a sample size of one and is intended to serve as an informative study, not a definitive judgment.


About Graham Baates“Graham Baates” is a pen name used by a 15-year active Army veteran who spent most of his time on the tactical side of the Intelligence community including tours in Afghanistan and Iraq. Post-Army Graham spent some time in the 3-Gun circuit before becoming a full-time NRA Certified defensive handgun instructor and now works as an industry writer while curating a YouTube channel on the side. Visit Graham on Youtube .

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Love all the crappy comments from people who have done no work. He said it several times in his article that this was not a scientific test and was just a minimal baseline. If you don’t like the way it was done get off your butt, grab some equipment, and do it your damn self. So sick of people wanting everything for nothing……


This was a great idea – if only you’d taken it seriously. (1/2 full mags because “it’s a lot of work” / sample size of 1 / unknown ages.)


I own a goodly number of both Brownell’s (30 rd) and NHMTG (20 rd) magazines and have gotten excellent performance from both – in fact, i don’t remember a single malfunction over thousands of rounds. Ditto with some USGI mags I have. The few Magpuls I own have worked well, too.

I see no reason to buy “off brand” magazines like some of those tested.

Ansel Hazen

Thank you Graham for the test. I don’t like anything that makes my S&W M&P15 look like an AK so I tend to forego 30 rounders. My collection consists mostly of Magpul 20’s with a few 30 round Gen 3’s too. For novelty several actual Colt branded have been purchased. All function without issue with factory or my own reloads. The collection grows when my eyes see 20 round MagPul’s go on sale.

American Patriot

Unless your using good & proper measuring equipment & techniques then your findings could be off up to .003. Then if your not starting out with equally new mags for all then what’s the point.

Graham Baates

Because we don’t always have equally new mags in our rifles.

American Patriot

If you really want to get technical If you’re not starting this project with a new product and using unknown worn mags then you’re basically measuring wear and not the mfr’s product spec’s. So again what’s the point? All the mags tested will probably work well to some degree, by Army standards during testing the P-mag came way out on top. I know though you just have to fill some space.

Clark Kent

This from someone who claims ‘time’ can change the angle of magazine feed lips. You have ZERO credibility, amigo. Hopefully you don’t inspect commercial airliners for a living.

Graham Baates

By time I was implying use. I’m sorry if that wasn’t clear enough for you.


Lots of interesting detail. This is also pretty true when it comes to various brands and types of magazines for pistols. When it comes to jams, stoppages, malfunctions or whatever, most of the time regardless of gun–it is the magazine. Hexmags were having a body bulging situation at one time. Unless it were for very short periods of time like under ten-days, I would not charge my magazines with ammunition as the author says it affects the mag. lips (spread) and for long time storage it affects spring pressure too. Then again, how the front of the lip is cut… Read more »


I’ll do a PS: The reason I found this particularly interesting is that I purchased three expensive magazines from a company you tested that didn’t do nearly as well, overall, as some of the others. I was really surprised as they (the ones I purchased) have a stellar reputation! Now you’ve helped me refine my search and save money. As you stated, Springs and followers can be replaced.

Wild Bill

@Vanns, This is good. Information that actually saves you money. Thanks Graham!


I have settled on P Mag and Colt ?? Day in and Day out different weapons, they run steady. With P Mags having an edge for ruggedness. But, big surprise, I bought three 30 Rd Pro mags at a gun show dirt cheap. I’ve read horrible reviews on them before and since, but they were cheap. They have been shot, abused, and hauled in the floor boards, and they seem to work great. Am I promoting them, no. I’m just saying you have to buy and use what works, and only real world experience is the answer, which is what… Read more »

Hey Jimmy

I have quite a few magazines myself and yes I have a good 10-12 Pro Mags and I have to be honest, they work and work well!! Pro Mag pistol mags are another story…


@Hey Jimmy, thanks for the reply. I have no experience with their pistol mags, but I had wondered about them.


Pretty doggone interesting, thanks.

Graham Baates

Thank you. I thought it might be interesting to take the springs and followers out of the equation for once.


Why was Hexmag not included

Charles Valenzuela

He tested what he had. Why don’t you send him one to test? Or just test it yourself to see how it compares? These tested mags give you a good base-line to compare any other magazine, which you may own. I only own mags in five brands, but two were not tested, so I tested them for comparison. Anyone can do that now that he has published results from so many well known manufacturers.