Keeping mags loaded - spring fatigue

[BajaJames83]

This is right. Compressed or not springs is fine for springs. It's the act of compression and release the puts wear on springs.

I suspect this myth comes from the rounds left in magazines that might get dirt and debris in the magazine. That debris could increasing static friction between the rounds and magazine body leading some to believe the springs have loss tension. So store as you like it doesn't matter. Maybe don't store them with your pocket sand reserves.

This exactly.
Depending on the finish the inside of a magazine can become sticky or corrode which can and will cause the rounds to stick to the inside. This was a huge problem with the Beretta M9 as many of the magazines had a phosphate finish which in dusty environments would attract and hold dust inside and many of the magazines would not function.

[robcoe]

Some say yes, some say no. I keep half of my mags loaded, half empty.

I do not think I will ever have time to use half of the mags I own in a shtf situation.

[BajaJames83]

Over compression can also cause damage but magazines are designed specifically to prevent that.

[Jeepergeo]

Is spring fatigue a factor when keeping magazines full and stored for long periods of time?

No.

[nitroxdiver]

[Latebraker]

Good info here. I see the logic. Thanks!

[QuinnBayArea]

No, that's a common myth. The spring loses it tension from constant usage.

This

[newbutold]

Keep them loaded and ready to evacuate if needed

[bergmen]

Do you keep a spare motor for that racebike? It has compressed valve springs the whole time it sits on the shelf. No worries.

Speaking of that (valve springs) how come the ones that are working all the time the engine is running don't wear out? Wouldn't that be the same as mag springs being compressed and relaxed constantly?

Dan

[GeeBee49]

Not much going on in my area so I don't have any loaded magazines right now but I would not be concerned about the springs if I kept some loaded.
My SIL is an LEO and he has several ammo cans full of loaded 30 round mags for his AR15s. He said they've been loaded for several years.

[redcliff]

Speaking of that (valve springs) how come the ones that are working all the time the engine is running don't wear out? Wouldn't that be the same as mag springs being compressed and relaxed constantly?

Dan

It depends upon how compressed they get and how high the rpm is, both of which create heat. On my normally aspirated BBC drag race engines with high valve lift and shifted at relatively high rpm (9k) we replaced them every 5 passes down the 1/4 mile. On a street engine with low rpm and low valve lift you can get 100's of thousands of mile.

[A-J]

Is it that time of the month for this topic?

Must be!

[sonofeugene]

It depends upon how compressed they get and how high the rpm is, both of which create heat. On my normally aspirated BBC drag race engines with high valve lift and shifted at relatively high rpm (9k) we replaced them every 5 passes down the 1/4 mile. On a street engine with low rpm and low valve lift you can get 100's of thousands of mile.

This. On your average street engine, you are never, ever going to wear the springs out. But if you stress them to the max, like in a drag motor, then you will see a change.

Same is true with mag springs. Under normal use you will never see wear from either storing mags full or from simply using them as intended. The springs and magazines are designed so that the springs never really get stressed in either situation.

However, if one was to "hotrod" their mags and subject them to higher than normal forces, then you might see some degradation of the springs. But who hotrods their mags? No one, I'll bet. They run their mags stock.

Spring wear in mags is a fairy tale.

[bergmen]

It depends upon how compressed they get and how high the rpm is, both of which create heat. On my normally aspirated BBC drag race engines with high valve lift and shifted at relatively high rpm (9k) we replaced them every 5 passes down the 1/4 mile. On a street engine with low rpm and low valve lift you can get 100's of thousands of mile.

Very good points, that makes a lot of sense. I wasn't thinking about the fact that normal street driving is not working the valve springs anywhere near the limit, resulting in almost unlimited life. I certainly see the need to replace springs in racing engines though. Good stuff, thanks!

Dan

[Duck Killer]

It use to be true for some older mags for example BAR mags. Not true for new mags. You can also get some cracked feed lips.