Straight out of the M4Carbine.net newsletter comes this statement by Ken Hackathorn:
GI style 30 round aluminum magazines are still a good choice, reasonable in price, and widely available. They do, however, bend and dent easily when dropped, stepped on, or left loaded for extended periods.
I thought it was okay to leave aluminum GI mags loaded? Now I find out this may not be the case?
I’ve literally never been able to get two people to agree on that. I’ve heard the same for Pmags too, everyone is always conflicted on whether it’s ok to leave them loaded. I will say I’ve shot both steel and polymer mags loaded for over a year. I’d like a legit answer.
Leaving them loaded does nothing.
You can leave PMAGs loaded. The polymer in the current mags is plenty strong. In addition, when using the covers they are particularly stable as the take pressure off of the feed lips. Even without the covers, you shouldn’t have a problem.
The question was about aluminum GI mags.
It would be best to contact Ken Hackathorn and ask why
The base plates on the USGI mags bend and can come off from the constant pressure over a long period of time. I have seen this with our extra stored mags. That is why people started to 100 mph tape the bottems of the USGI mags many years ago.
I have PMags that have been loaded for years and they are good. I have a few set aside just to see how long they will last…
The question was about aluminum GI mags.
I’ve literally never been able to get two people to agree on that. I’ve heard the same for Pmags too, everyone is always conflicted on whether it’s ok to leave them loaded. I will say I’ve shot both steel and polymer mags loaded for over a year. I’d like a legit answer.
It was in response to the post directly below yours.
That’s good news. Putting a few strips of Gorilla Tape on the bottoms of all my loaded mags is much easier than having to unload all of them!
I’ve got USGI mags that have been loaded for years… maybe near 10 or so. No issues.
I figured loading to 28 like he does would make this a non-issue with aluminum mags.
Have only ever had one issue with a USGI mag that was left loaded. Had a Brownel’s 30 rounder that I bought back in Jan 13 along with a a few Lancers I bought to try because my LGS had them at like $12 during the height of the SH panic. Bought it, function checked it at the range, worked fine then played with those neat Lancers. Loaded the Brownell mag to 25 or 30 rounds, don’t recall and left it set on a shelf for about 3 months. unloaded it when I built a lower I had laying around and inserted it in the lower to check and make sure the mag catch worked. Mag wouldn’t drop free, thought the lower was jacked up, grabbed another rifle. Still no drop free, ended up checking about 6 different rifles/lowers including the ones that it had previously dropped free from and it stuck in all of them. Needless to say that mag went down the road. Only USGI mag I have ever had do that though, and I have other USGI mags that have been kept loaded for 6 years plus that I just unloaded to cycle, and they all worked fine, dropped free, ect, so I just considered it a fluke, and have heard issue with the Brownell mags having some issues from that time frame. Am looking to order a few here in the next month though to try again though.
I also have USGI mags that have been loaded to 28 rounds and they are perfectly fine. I have PMAG’s that have been loaded in the safe to 30 rounds now for 2-3 years and they are perfectly fine.
I have kept several mags loaded for years, no issues…seems frequent loading and unloading would be more stressful. On the other hand, the mags are a more disposable part of the rifle anyways.
i researched this 25 years ago. spent time talking with the the owner of wolff springs.
“spring set” is only a problem with poorly made springs, not with quality springs.
what wears springs out is compressing/releasing them over and over again.
aluminum mags that have quality springs may be left under compression without harm.
I think the issue being debated at present is whether or not the metal tabs that hold the floorplate gradually fatigue and bend if the mag is left loaded for an extended period of time. That’s why some suggest the duct tape fix: it theoretically removes some of the tension off those metal tabs.
That is correct. Those little tabs are the weakest part of the mag.
I think the issue being debated at present is whether or not the metal tabs that hold the floorplate gradually fatigue and bend if the mag is left loaded for an extended period of time…
my bad. i thought it was about any issue for not leaving them loaded.
but that said, the same answer may apply: maybe its the stress of loading/unloading which flexs of the tabs that causes them to fail. would simple leaving-them-under-pressure cause the tabs to fail?
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Unless the tab were cracked during the forming process, that relatively small load on these tabs should not be a problem.
Fatigue would only be a problem after several hundred thousand unloading/loading cycles.
so i imagine putting tape over them would do little to help, if anything?