Explosive Failure of Polymer AK Magazines… From Sitting In A Safe?

    Ever seen a magazine explode? Lee “The Gun Writer” Williams was greeted by the aftermath of this dramatic failure of a Bulgarian AK magazine, little more than a week ago:



    AKMag 004

    I had a surprise last night when I opened my safe.

    The top of a loaded polymer AK mag had broken off for reasons unknown, spraying 28 loaded rounds and bits of plastic all over my safe.

    The spring was sticking halfway out of the top of the mag. I found the follower behind an SKS.

    To be clear, the mag was not in a rifle. It was one of several loaded mags I keep on a shelf of the safe.

    The offender was a Bulgarian slab-side polymer magazine, which is usually considered one of the better mil-spec-type AK magazines

    It hadn’t been loaded for that long, maybe a couple weeks. I rotate my magazines between trips to the range to give the springs a break. And as I said, it was loaded with 28 rounds, not 30.

    The lesson I learned: The best AK mags are still the Combloc steel.

    They’re a bit heavier, but the extra durability makes them well worth it. You can nearly play hockey with a steel AK mag without worry. They’re also easier to pull out of a chest rig than the waffle-sided variety.

    AKMag 002


    Hognose had further commentary on his blog, WeaponsMan:

    What makes a mag fail like this? Lee seems to think that the guilty party is leaving the mag loaded for a length of time. We have our doubts about that and would be more inclined to suspect the cumulative effects of age and ultraviolet-ray exposure (plain ordinary sunlight, which it certainly couldn’t have gotten in his safe). But the durability of different AK mags, even different Bulgarian mags, is widely variable.

    We also don’t think loading only 28 rounds buys you anything. The difference in pressure is nominal. This goes back at least as far as Vietnam and was a ritual practiced by troops (although, there it was putting 18 rounds in a 20-round magazine) who were neither trained on the rifle nor given a supply of replacement magazines. It was something they did to appease the M16 Gods

    The plain ugly fact is that magazines are, by design, expendable items and you need to start thinking of them that way — they’re the toilet-paper of small arms, necessary but not especially durable or reusable. And just like toilet paper, some brands are better than others. Lee, for example, probably should dump all of his circle-10s that are the same age as the one that failed, because their clock is ticking, too. Sorry to be The Bearer of Bad News.

    In the real world, private owners and armies alike are reluctant to purge their bad magazines because the mags represent a considerable cost — both the sunk cost that was spent on them and is lost for good, and (more germanely) the replacement cost for new mags. It is possible (although not necessarily economical or practical) to repair or overhaul metal, especially steel, magazines, but synthetic materials are harder to repair and rebuild.

    I’m inclined to agree, but I’d add that another possibility is a materials defect. The magazine failed where the steel feed lip inserts were molded into the polymer, a manufacturing technique that requires its own science and witchery to perfect.


    H/T, Hognose, of WeaponsMan

    Nathaniel F

    Nathaniel is a history enthusiast and firearms hobbyist whose primary interest lies in military small arms technological developments beginning with the smokeless powder era. He can be reached via email at [email protected]