Testing how well Magpul PMAGs hold up against chemicals

The owner of an Army surplus store, United States Army Reserve Warrant Officer and commanders adviser on maintenance issues, wrote about his experiments testing how well Magpul PMAGs hold up against some of the chemicals that soldiers sometimes carry.

I look forward to further testing. It makes sense to test how well the polymer magazines you carry hold up against the chemicals you carry, just as it makes sense to see how much abuse your aluminum magazines can withstand.

[ Many thanks to jdun1911 for emailing me the link. ]

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • Jpow

    How about looking at what polymer they use and find out what it reacts with from literature? A lot of polymers will react to cholrine for example.

  • Vhyrus

    Simple chemistry will tell you 90% or more of the chemicals that will or will not break down certain plastics. There’s no need to test all of them.

  • noob

    Do we know what polymer MagPull uses exactly or is it a special secret blend?

    • 6677

      I don’t know if its a complete secret as a chemistry lab could theoretically work it out but I don’t think they publish it if thats what you mean.

  • Robin

    I remember when I was in the Army and had a bottle of bug juice (insect repellent) leak onto a Angle head flashlight. The plastic melted and remained gooey for quite some time til I finally threw the flashlight away.

  • We test the PMag with over 10 types of chemicals to gauge their resistance. The PMag body is resistant to DEET and all other chemicals relating to the M4/M16 weapon system.

    The only issue is with the clear window on the Maglevel PMag which can become frosted when exposed to certain chemicals. That said the window is very resistant to DEET and most common cleaning agents and even when affected it does not compromised the strength of the magazine itself.

    • Mike Knox

      Uhh, dood. You might want to look into his test..

      • Some guy

        Uhh, dood. Richard Fitzpatrick is the founder of Magpul.

      • Mike Knox

        @Some guy
        Have you read the linked page? I’m sure not..

      • The linked page shows exactly what I said. The affected area is the clear window part of the magazine.

      • Mike Knox

        @Richard Fitzpatrick
        Just the window? The LSA test resulted in feedlip crack when dropped after cleaning with winchester gun wash.

        DEET exposure test resulted in stress cracks in the window. Unlike what you’ve said “window is very resistant to DEET and most common cleaning agents”. DEET caused fractures in the mag.

        You really might want to read the test again, thoroughly..

      • W

        “The LSA test resulted in feedlip crack when dropped after cleaning with winchester gun was”

        I think you are incorrectly drawing to conclusions. The tester even admitted, “My conclusion- indeterminate. Yes, the feedlip cracked after one drop. However, we have seen several failures in the same area on here and elsewhere on the net, so I can’t say this was from any weakening. I could see no obvious issues that I could beyond a reasonable doubt say were from the LSA. My gut tells me that the LSA wasn’t a factor and it probably would have cracked the same way had I dropped it fully loaded as soon as I opened it. But once again I don’t have a lab, testing materials, and only tested one mag, so don’t take anything from this test as gospel, do your own testing and research. It seems very likely to me that this was just a bum mag that cracked when dropped on the weak point. ”

        Youre dropping a a loaded magazine on its feed lip on concrete. dont be surprised that this can happen. Aluminum and steel magazines can dent too, with results less catastrophic, though its about tradeoffs.

        The window remained soaked in 100% DEET for a long period of time. That is different than occasionally getting skeeter dope on the magazine after youve applied it on yourself. You dont carry skeeter dope in your magazine pouch anyways and that stuff is notorious for melting things besides polymer magazines. Richard Fitzpatrick said it is resistant, not “proof”, which is certainly the case; the DEET was allowed to stay puddled on the magazine side window for 24 HOURS…

      • Mike Knox

        Rigid Polymers, no matter what the composition, rating or geometry, are always supceptible to chemical agents. Knowing from injection molding processes, material propagation is a factor with integrity along with it’s geometry. During moulding, there’s still a grain that flows along with the material, slight irregularities in the material that’s easily affected by whatever weakens polymer strength, especially chemicals. With that and a simple shock, there’s the immediate effect of a fracture.

        Metal Magazine lips can still hold the cartiges even when dented. Polymer mags however crack, comprimising it’s contour strength, and fail to hold in the cartiges more often than not. Another thing, ‘resistant’ and ‘proof’ mean the same thing.

        I’m certain it won’t be long before you come up with complications along with your response. My responses to “Richard Fitzpatrick” and his are based on absolute statements, not uncertainties and assumptions. Don’t tag along if you’ve only got either or oblique statements..

      • W

        yup and nobody says otherwise. that is the nature of polymer. that is why i emphasized “resistant” instead of “proof”.

        If they’re dented, they also cannot reliably cycle, if at all. and the two terms are not the same. By saying chemical-proof, you are implying that DEET or any other chemical is completely incapable of compromising the integrity of the product. By saying “resistant”, you are implying that it will be less likely that there will be a breakdown of the product, though it is possible within a certain window of time.

        look, you need to start paying attention. nobody is implying that the product is DEET proof, though he (richard) is saying it is very resistant, which it is demonstrated to be by the test (being puddled for 24 hours by a chemical that is known to deteriorate other items in the army inventory). You somehow think that he’s saying that his product is chemical-proof and he should look at the test because it says otherwise. If anything, it bolsters his statements that pmags are indeed very resistant.

    • Mike Knox

      Magazines feed, not cycle. Metal magazine feed lips howver need to be significantly dented to cause retention failures or obstructions.

      ‘Proof’ already means resistant, meaning a natural counteraction to an effect at a complete degree. If it were resistant, there would have been no stress fractures or immediate cracks causing failues unlike in the test. It is as simple as that.

      Unlike what you’ve said, somebody already has claimed it to be DEET proof, i.e. “Richard Fitzpatrick”. And the solid and obvious fact that the pmags has encountered damage when exposed to chemicals. As evidenced contrary to your claim, pmags have weaknesses, more prone than stated.

      Evidential statments published in the link against your speculative statements prove evident that despite company calims, the pmag isn’t as resilient as stated..

  • Reverend Clint

    shotgun news tested pmags, lancer, aluminim and steel gi mags, tapco i think and some other ones. http://www.thefirearmblog.com/blog/2009/11/25/shotgun-news-test-ar-15-magazines/ i think he dipped them in bleach, diesel fuel and maybe gas.

  • Lance

    As long as you wipe them down and take care of your mags they will do fine no matter the brand in use.

    • Al T.

      “no matter the brand in use”

      I’m fairly sure you didn’t mean that a ProMag will run with a Pmag. Get good magazines, don’t marry them, mark’em and throw’em out after some hammer therapy when they wear out.

  • Just want to add a couple of comments. Polymers consist of a gargantuan chain of carbon hydrogen chains like this

    H H
    | |
    | |
    H H

    Anything that attacks the Carbon to Carbon bond or H to H bonds will zap the polymer. The good news is that those bonds are tough to break and it takes the right combination of heat and chemicals. This is one of the issues with polymer cased ammunition and prolonged storage in less than optimal conditions. Certain pesticides (and bacteria) luvvvvv polymers and will break it down. It doesn’t make the concept of polymer magazines bad, its simply something to look out for.

    This link points to dynacorp labs and they list a variety of polymers and their ability to deal with certain chemicals.

    Hope this helps.

    Moral of the story? Keep your shit clean…

    • Small correction: Carbon to Carbon bond or H to H bonds

      should read Carbon to Carbon bond or H to C bonds

      • 6677

        I was just thinking that. We all make typo’s anyway.

        Don’t forget we’ve got polyester (PLA, terylene) and polyamide (nylon, kevlar) polymers too.

        According to A2 chemistry textbook from school, aqueous acid or hot aqueous bases will break apart the chains in both polyesters and polyamides. Both need to be in a reasonable concentration. Although it doesn’t specify what reasonable is.

  • Darrel

    Not to take a crap all over Pmags, but the fact that it broke near the back is a huge red flag for me. I’ve never had a problem with mine, but I’m also pretty careful.

    With the claims Magpul makes, I should’nt have to worry about dropping my mag out of a two story window onto concrete.

    Chemical test is useful though. How do they perform after being dropped in petrol for a couple days? I think magpul makes some mention of this?

  • not conventional

    I’ve done two deployments to OEF and neither time did i or any other soldier i knew carry “chemicals” other than CLP (in a little bottle at most). If you have chemicals that are detrimental to your equipment on your body then i have no concept why. The possibility of you running through the motor pool in full kit exists but something has gone terribly wrong at that point. The point is yes the military has extremely harsh chemicals, however you would most likely never be in full kit while using said chemicals. This is an example of someone trying to find flaws with equipment that shouldn’t be exposed to said situation. PMAGs wouldn’t survive a nuclear attack or a meteor so lets get rid of the big army, Idiots. I’ve use PMAGs for 5 years (2 of those in country) and they work. those tan follower “new and improved” mags are still crap, they still dent when you drop them, the feed clips still bend, and like all mags you can’t leave them loaded for long periods of time (except to unload a tan-foller mag its a pain in the ass because the spring is a beast)

  • Charles222

    Well, one, you shouldn’t be making your magazines co-habitat with anything else in the magazine pouch. Two, about the only chemical I’ve seen regularly used with magazines and ammunition is CLP, that weird “dry” lubricant (graphite iirc) that I was issued in Afghanistan, and the occasionally tuf-cloth. Which is an awesome product, btw.