How long do you store ammo in a mag?

ddawg

Senior Member
Thread starter #1
I just traded for some Boxed & loose .223 for my AR. I'm thinking about buying some cheap GI mags and load up the loose ammo to put back for reserve.
how long can you leave ammo stored in a mag without running into problems w/ the springs?

Thanks
 

germag

Gone But Not Forgotten
#2
Years.
 

wareagle700

Senior Member
#3
I have some that have stayed loaded (30rnds) the past 4 years. They are still going strong. I bought some extra springs for just in case they do give up, still in the wrapper though.
 
#4
+1 for years. Leaving the spring compressed isn't what causes problems. Its compressing and then un-compressing (probably not a word) that wears them out.

But be careful buying cheap mags. Invest in quality mags that aren't going to fail on ya.
 
#6
I'd start with fresh springs and then load 28 in the 30 rounders and 19 in the 20 rounders.

They ought to be good for years.
 

BigHutch

Senior Member
#7
Got a Ruger P95dc that has been loaded for 14 years, gets shot very rarely. Probably has only seen about 50 rounds in those 14 years. They all went off just fine.
 

BookHound

Senior Member
#8
There are really two issues regarding leaving magazines loaded for extended periods when it comes to AR-15 style firearms. Most folks want to focus on the springs and that is certainly one of the two issues. The springs in quality AR magazines will not "take a set" like some people think. As already stated in this thread the springs wear out through use.

The second issue is the feed lips. Some USGI magazines have weak welds on the spine and these welds can result in the magazine feed lips opening up slightly. This is not a common problem though and is limited to certain manufacturers who produced magazines under contract over the years. I want to say some of the Sanchez magazine fall into this but am not 100% certain (going on memory). Other magazines like the popular Magpul PMags can spread at the feed lips too. This is why later revisions of PMags were sold with a clip that holds the feed lips tight if you want to leave magazines loaded for longer periods of time.

Now, regarding number of rounds to load...

I'm also a "28 in a 30" guy. The reason is that the curvature of the 30s causes magazines to sometimes bind and not seat properly on a closed bolt. Heck, I've had that happen many times even with 28 rounds in the magazines. But the common 20 rounders (to include PMags and USGI) are straight magazines with no curvature. These will seat just fine on a closed bolt even fully loaded (20 rounds). But, do what works for you and what makes you feel best.

I strongly second the "buy quality" comment when it comes to magazines. The feeding system is the biggest single point of failure for auto-loading firearms. Especially if you ever could possibly use that magazine in defensive situations. Saving a couple bucks isn't worth it.

The other guys are spot-on though regarding years. I've got (and used!) many AR-15, Glock and other magazines that have been loaded ten or more years. I've personally shot AR mags that were loaded for 10+ years and had zero problems with feeding.

Take care,

Mark
 

sea trout

Senior Member
#9
book hound is shootin you straight!
i have 8 mags for my mini 14. 5 are ruger brand, 3 are cheap brand.
i keep my mags loaded to the gills. never had any issues with ruger mags but one of the cheap brands the feed lips have spread and opend up. it caused a feeding issue so i threw it in the trash! nothing ever changed with the springs though, not even on the cheapies.
 
#10
Didn't consider the feed lip problem bookhound. Thanks for the tip.
 
#11
1.] Don't buy cheap mags

2.] Don't buy cheap mags

If you can, take the mags apart, clean and lubricate, even if new. I've fired Luger (P08) mags that had been loaded and stuck in a closet for 30yrs with nary a hiccup.

Clean mags are happy mags...
 

Wiskey_33

Senior Member
#12
What are "cheap" mags?

I have only C-Products mags, and they're all loaded with 28 rounds. Never had an issue even though I paid less than $10 each for new mags.
 
#13
I keep my magazines loaded until I decide to shoot them. Some have been 'loaded' for twenty years or more.........no problems. As a retired engineer and former metallurgist I can tell you all this talk about 'springs take a set' is mostly over rated hype meant to sell you something. Good springs will last longer than you or I.
 

throwdown

Senior Member
#15
I'm with Wareagle, I replace the springs as need be on my older mag's, but the newer generation springs are so much better. I keep all of my duty AR mags loaded to the gill, they hardly ever see the light of day, and do just fine. I do however only run P mags.
 

bullgator

Senior Member
#16
A few years ago I read an article stating that by loading a hi-cap mag just one round short, it would increase the spring life something like +70%. It seems like they tested several mags, but I'm not certain about AR mags. I do remember that handgun mags were tested.
 

germag

Gone But Not Forgotten
#17
A few years ago I read an article stating that by loading a hi-cap mag just one round short, it would increase the spring life something like +70%. It seems like they tested several mags, but I'm not certain about AR mags. I do remember that handgun mags were tested.
That test must have taken many years to complete.

Unless you are exceeding the elastic limit of the spring steel, loading to capacity or leaving loaded will have zero effect on the steel. The engineers that design magazine know what they are doing. They are not going to design a magazine where you can exceed the elastic limits without first altering the springs. If you tweak" your magazine springs, then all bets are off....but you did that yourself. Brass and copper and such metals as that have a lot of creep...so you don't make springs out of those materials. Steel has no appreciable creep at all unless heated to extremely hot temps.

These myths have been around at least since Vietnam that I know of. Everybody always said "Don't load more than 19 in a 20"....even though the mag wasn't likely to stay loaded long.

That's not to say it isn't possible to have feeding problems from leaving a mag loaded for a long time...depending on the lip edge angle it could cause the cartridge case to deform, and as Bookhound pointed out it could cause deformation of the feed lips in some magazines. Other than that, there is no reason not to fully load and leave loaded a high quality magazine.
 
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#18
I'm with Dave in N GA, I leave mine loaded till I shoot em and they are all cheap mags and they all shoot without fail. I have left mine loaded for a long couple of weeks but they are all loaded.
 

LaRue

Senior Member
#19
What are "cheap" mags?

I have only C-Products mags, and they're all loaded with 28 rounds. Never had an issue even though I paid less than $10 each for new mags.
They are out of business for a reason though. I'm not suggesting anything...but saying that it is something I'm not so sure about.

When they were around, I always saw tons of people praising them for their customer service. Why? Because they had a great experience when returning and exchanging bad magazines.


As for what Bookhound said about the Pmags... some Magpul reps have come out saying that the covers aren't necessary and that the feed lips keep spec anyways. But who knows...

I'm in the buy quality camp...I'm also in the "anything man-made can fail" camp. I load 20s in my 20s. I load 28 in my 30s though I never worried about my springs or feed lips but loading difficulties.

Buy good mags, test them, have backups. Always have backups. Weakest point of your weapon...gotta keep the rapid-change loaded spare parts kit on deck.
 
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