Bingo! Aluminum is the problem here. If a steel wire can support a max of 100 lbs. today, it can hold that weight forever in theory. If an aluminum wire can support a max of 100 lbs. today, it will eventually break. If you hang 80 lbs. of weight from the aluminum wire it will eventually break. Aluminum fatigues differently from steel, a constant load, even below the max force, will eventually cause deformation.I've only heard that in reference to AR mags...the aluminum ones.
The phenomenon you are describing is creep not fatigue. Fatigue is crack growth under cyclic stress. Creep is increasing strain under constant stress.Aluminum fatigues differently from steel, a constant load, even below the max force, will eventually cause deformation.
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Originally Posted by DeepSouth
I have heard (which means I don't know) some of the older aluminum AR mags were pure junk, some even considered "disposable" after the first use. Don't know if there's a connection but it sounds at least plausible
Unless there has been some change my understanding is that all aluminum magazines are considered disposable. That was quite a shock, back in the day when H&K-91 mags were $45
Somebody GAVE them to you? Was this like the family of a veteran who had passed away? Who gets as lucky as to have a dozen bring-backs given to them? I'm seriously jealous.In 2001 I was given almost a dozen WW II "bring-back" semi-auto pistols
It does make you wonder why MagPul added the lip saving covers