[HerrZnk]

Wondering if anyone has actually experienced magazine spring "set", i.e. feed malfunctions due to a magazine being left loaded for an extended period. I personally have never experienced such; I do rotate through magazines on a pretty regular basis in all firearms which are kept stored with loaded magazines, or magazines which are stored separately, loaded.
What prompted this thought was that I was doing PM on some of my East German PiM "Makarow" pistols & while going through the safe found a magazine that has been loaded with EG AP* ammunition for at least 10 years. Just for the fun of it I went out back & fired a pistol using this magazine; functioned flawlessly. Followed by a nice clean with soapy water then Hoppe's.
Has anyone experienced any such malfunction? What's the longest you've stored a magazine, either in a detachable or fixed (such as a tube in a shotgun or tube-fed .22)?

*9x19mm steel-cored corrosive ammunition manufactured in the Deutsche Demokratische Republik (DDR) aka "East Germany", which is considered AP as it was designed to defeat body armor, not tank/APC armor. This was imported by the pallet by a company back in the 1980s after German reunification - until the BATF realized it was AP handgun ammunition and they swooped in to confiscate it. Fortunately some had realized what it is and had purchased it by the case before it was shut down.

 

[Mesquite]

Think only one I'm aware of was a cheap(no name) 1911 mag i picked up years back.

 

[HerrZnk]

Think only one I'm aware of was a cheap(no name) 1911 mag i picked up years back.

Do you happen to recall how long it had been loaded prior to the malfunction?

 

[Dave]

Springs wear out from flexing. Loading and unloading magazines is where the spring fatigue is created. A poorly tempered spring could develop spring set. A slight amount of spring set does happen even with a well made spring. It isn't normally enough for you to notice it.

 

[para40]

Springs wear out from flexing. Loading and unloading magazines is where the spring fatigue is created. A poorly tempered spring could develop spring set. A slight amount of spring set does happen even with a well made spring. It isn't normally enough for you to notice it.

Truth!

 

[Mesquite]

Do you happen to recall how long it had been loaded prior to the malfunction?

No, but couldn't have been Long time, think it was just cheap start with.

 

[Quickeye]

Springs no longer spring when they exceed their "elastic" limit. Called "scragging" in the spring makers trade. It applies to already hardened and tempered spring steel, would around a mandrel.
(1.0 C,- .4 Mn and .7 C -.8 Mn; annealed at about 780Cel.).
Springs (compression or expansion) lose their spring when they become plastic, achieved by exceeding the elastic limit.
Springs are difficult and expensive to make, mainly because of the heat involved to produce them, direct flame is not used, notwithstanding the cost of the alloying elements to the basic carbon steel.
So to address the OP's question. A spring can take a set, usually because it has left Martensite stage and entered Bainite during forming.
So it depends on what alloys were used to form the spring in the first place, and if it was heated, hardened and quenched at the correct temp and for the correct period of time, or whether or not it was already formed and then wound or coiled around a mandrel. Yes, it is possible for a spring to take a set, but unlikely these days using modern techniques and alloys.

 

[Quickeye]

50 years ago, I never loaded a mag with more than 18, if I was counting.
Also probably why the Army didn't issue pre-loaded mags. (See @BasMstr magazine loading method)

 

[Jarhead5811]

Not long ago my sister-in-law gave me a polymer AR mag of unknown make that was loaded for a “long time”. (Apparently her husband had an AR more than a decade before. So, it was at least that long.) I put it in a rifle and once the first round stripped off the rounds wouldn’t move up. I knocked it around to get the rounds out, and threw the POS away.

Otherwise, I’ve never seen such problems and I think a quality product is unlikely to have the issue. I load AR mags full and then strip out two rounds. It’s a habit I learned in the Marine Corps. I’m not completely convinced the thinking behind it is solid but I figure whoever decided it was the way to do it knew more than I do. So, I still do it.

 

[BasMstr]

So far, this is the only magazine I've had any issue with. I just set it aside the day it happened to me and Bobcat, then "marked it" later. Probably loaded for over two or three years, but I actually think the feed lips got spread (asked Bobcat to load some magazines for me, remember checking one later and it had 31 rounds in it - mighta missed double checking this one). I leave all mine loaded at 30 rounds.

 

[2DARK2C]

in soviet Ruska spring sets you.