And taper crimp..that is part of the problem. Even cartrideges that headspace on the case mouth can be toll crimped .002. That edge in the roll crimp makes a huge difference.

Hey, it’s Springfailed!

Depends on the gun. I understand external extractors are usually immune to this. A definite no in a standard design 1911

Yes this. I've loaded my mags to full capacity or close and I'll probably just take some out in the near future or not. Metals from different sources will happen to respond differently... probably the reason why we are encouraged strongly to buy lots of mags so in case these fail, it's grab the next one. You'll find that mags will stick because of their pot metal like quality or their easily corroded metal like aluminum that might tend to 'stick' having two different metals in them. They can work but to a point where I've found them at ranges in different states of disrepair. They're like 5 bucks or close to that? they're not gonna survive long and they really aren't meant to unless you are really meticulous about them and the prevention of their exposure. Not exactly rocket science although springs have been the source of rocket engineering, it's use at your own discretion.

And maybe buy some replacement springs to have on hand in case you have one or more go bad.

Also another thing... If your defensive ammo is too expensive to initially fire a box of 50 rounds, then every couple years cycle some more, then you need cheaper ammo or a bigger gun.

What i mean is initially you should cycle the gun to make sure it wont misfeed, especially with various hollow points. From there, every couple years make sure everything still likes your ammo(incase it gets fowled or worn and cycles differently). I guess where i'm going, is you shouldnt be in a position were a mag stays loaded for 12 years

I do shoot the same rounds (defensive rounds) I reload out of that gun. Price of the ammo meant nothing in my keeping the mag full. I left mag loaded for 12 years, because as I understood it, there is no problem leaving it loaded, the problem was cycling the mag and weakening the spring and giving a chance of fracturing the metal. The last I time I shot it, was to run through the ammo and see how the mag worked. I'm really glad I did that or I would have not seen the issue of the twisted spring.
You are right, I will not be keeping ANY of my mags loaded for more than one year. Every mag I use on a monthly basis has worked flawlessly for more than the 12 years. I will now cycle through mags and I have stocked up on new (never used) mags and extra springs as well. I'm glad I got all of that before the crazyness that is about to happen with the ban!

True but it isn't sitting bottomed out. Magazine springs are designed with a greater percentage of travel in mind but ita still possible to have a failure in that range on compression. I bet I'm not the only one who's fully loaded a vehicle down to their bump stops and broken a relatively new coil without even driving anywhere. Some of this is why pickups don't have coils though. Either way a mag spring should be designed to rest at full compression, but there's a lot of variables that can confound that. Who knows, maybe this mag was always bad as some have guessed but it could have just needed a few more cycles to show it before going into storage. Or there was an issue with the spring design that doesn't take into account pressure from the bottom of the slide against the top round? I've seen some poly mags with bad floor plates that were applying extra pressure from below...

...so yes let's all just buy more spares!

I'm 55, so my mags' springs most likely will survive me.