I read somewhere.....Magazines from WWII, filled with ammo for 50 years, worked perfectly fine. The ammo, if stored properly, without moisture getting to them, fired every time!!!! Still good!!! kjdfjemndweiweinp Bob
Last year while going through some old shooting stuff in a duffel bag. i found two model 39 9mm magazine loaded to the max. My model 39 was stolen in 1983 and never recovered. When i found these magazines i had just purchased another model 39 " finally " that means that these magazines had been loaded for over 35 years.. Well I loaded them into my replacement model 39 and the ammo shot fine and the magazines worked perfect. And are still working .
I had been told by someone whose opinion I respect that springs wear and fatigue as a result of springing. Keeping them compressed or uncompressed has no effect and its actually better for the spring to be compressed rather than unloaded and reloaded. Its the act of compressing and uncompressing that actually causes the fatigue. Having said that .. I dont really give it much thought. I dont shot my plastic 9mm much but its been loaded since i bought it and always works
A friend's uncle bought a house in the 1970s and in the attic we found a military bag that among other things had a 1911 with a loaded mag, later we fired the gun only the last round in the mag stove pipe.