View Full Version : Loaded Mags. How Long?
Howdy,
Pre-2020 I'd shoot at least once a month if not weekly so mags got rotated and used frequently.
With ammo shortage I'm not shooting my AR as much.
Most of my mags are PMags and assume they can be fine for months like this...or am I wrong?
I'm not in a position, at the moment, where I need 10 mags loaded; but there they sit waiting for another ammo score! I figure I best not shoot more than I can replace at least 50% of and it's been hard to find more than 40 rounds at a time it seems...No where within 100 miles had any last loop through the gun shops...
Thanks!
Most of my mags are PMags and assume they can be fine for months like this...or am I wrong?
You are wrong, they can be left for YEARS and be fine.
I still have Pmags that I loaded back in 2013 that shoot fine.
The_War_Wagon
12-02-20, 11:28
http://youtu.be/sgJXbIP83A8
tanksoldier
12-02-20, 11:48
Modern springs can sit under load forever with no notable degradation.
What wears them out is use: loading and unloading.
A couple of first generation FDE PMAG's loaded in 2009 and left that way until this year worked fine.
Modern springs can sit under load forever with no notable degradation.
What wears them out is use: loading and unloading.
Yarp. Cycles cause wear. Pretty universal.
Don't worry about it...Like others have said, you can leave them loaded basically forever.
IMO, having 10 loaded mags on hand at all times is never a bad idea. I also think your plan to only shoot what you can mostly replace and to not deplete your supply too much is prudent.
Probably should have stocked up more during the last few years, but I don't know how long you've been at this or what your situation is like, so I'm not gonna harp on that too much...Something to think about if we ever get cheap, plentiful ammo again, though.
Modern springs can sit under load forever with no notable degradation.
What wears them out is use: loading and unloading.
This ^^. It's not sitting loaded that affects their life, it's constant loading and unloading. I've had mags loaded for years that work perfect after sitting that long, so you should be good to go storing them loaded long term.
I remember the "rebuild kits" for mags back around the ban era. So dumb... A mag's spring will out last the mag body by a long shot.
I remember the "rebuild kits" for mags back around the ban era. So dumb... A mag's spring will out last the mag body by a long shot.
You’re misunderstanding the real purpose of rebuild kits.
I have had something Okay magazines loaded in 2012 and I don’t worry at all leaving the springs compressed in the magazines. If you shoot the magazine and reload you are causing some wear on the magazine but it take a lot of cycles to wear out the magazine springs.
I take the same magazines to the gun range for years and never had a single failure with magazine springs. I am fairly new since I bought my first AR in late 2010.
Longer than the search function takes that’s for sure.
ammodotcom
12-02-20, 13:58
Amen to that, those things' springs don't care one iota about being left loaded.
titsonritz
12-02-20, 15:14
Modern springs can sit under load forever with no notable degradation.
What wears them out is use: loading and unloading.
Yep. It crack me up when people unload their mags to "save their springs" when in fact they are doing the opposite.
titsonritz
12-02-20, 15:14
Longer than the search function takes that’s for sure.
:lol:
You’re misunderstanding the real purpose of rebuild kits.
The last thing a "rebuild kit" was for was rebuilding a mag.
Captains1911
12-02-20, 21:06
I have 6 gen1 pmags that have been left fully loaded since about 2008, with the dust covers on, and all still function fine. I have several other non dust covered pmags and lancer mags that have been loaded for at least 5 or 6 years, that also function.
Yep. It crack me up when people unload their mags to "save their springs" when in fact they are doing the opposite.
Do you know how many cycles it takes to kill a spring?
titsonritz
12-02-20, 23:39
Do you know how many cycles it takes to kill a spring?
A lot
owner of wolff gun springs once told me that if built with modern high quality springs, they can be left loaded forever
you load one down and leave them and they will be as good as new. Have used mags loaded for over a decade that ran like brand new
Captains1911
12-03-20, 20:58
you load one down and leave them and they will be as good as new. Have used mags loaded for over a decade that ran like brand new
Or don’t load one down and get the same result.
I remember the "rebuild kits" for mags back around the ban era. So dumb... A mag's spring will out last the mag body by a long shot.
Yep. I’ve worn out base plates & followers but never a spring.
Believe it or not, this mag was still feeding when I discovered this.
...and yes, Magpul replaced the mag free of charge.
https://uploads.tapatalk-cdn.com/20201204/869bb92beb1ab7bf826f1fae3bda1200.jpg
https://uploads.tapatalk-cdn.com/20201204/98b4b7aebd089494d7ceae9e9af234bc.jpg
https://uploads.tapatalk-cdn.com/20201204/3b0407e149a28b0392c16eabc1466249.jpg
https://uploads.tapatalk-cdn.com/20201204/7d08485141239e32decf53b4a5d48d2e.jpg
The only thing I've noticed with polymer mags is that if you leave them loaded for a long time, like months to a year, they will bulge, and the stack can kind of spread and jam up. The only problem this has caused me is trying to load a mag on a closed bolt. If the mag has bulged and you try to slam it on home, it gets jammed up and won't seat because the stack shifts and binds up in there somehow. If that happens, all you have to do is slam the mag down on its butt and the rounds will right themselves.
Because of discovering that issue, I have switched to metal mags. I only use Okay Industries GI mags with the tan follower. They are hard to find, but they do come up from time to time as Colt branded mags (which are actually just rebranded Okay mags). The bulging issue combined with the possible feedlip issue has just really turned me off of polymer AR mags.
I'm in year 20 of carrying a handgun on my belt and have never changed the springs in my duty mags.
The_War_Wagon
12-04-20, 07:06
The only thing I've noticed with polymer mags is that if you leave them loaded for a long time, like months to a year, they will bulge, and the stack can kind of spread and jam up.
Brand, please.
Or don’t load one down and get the same result.
you can do that but you run the risk of lip issues which is what people should worry about and not the spring. Loading 1 down completely removes this concern
dwhitehorne
12-04-20, 07:12
I have 6 gen1 pmags that have been left fully loaded since about 2008, with the dust covers on, and all still function fine. I have several other non dust covered pmags and lancer mags that have been loaded for at least 5 or 6 years, that also function.
Some may remember when Magpul mags first came out and they had us exchange all the mag bodies with new ones. I have a few of those still loaded all this time. I used one last year and it worked fine. David
Red the Monkey
12-04-20, 08:55
I have mags that been loaded constantly with ammo since 2007 with no issues. I think you’ll be fine
Brand, please.
All of them. Now I can't claim to have used them all, but I've used the big 3, plus some other less common ones. They all do it. The reason they all do it is because they're all exactly the same throughout the area that goes up into the magwell, which is the area that is problematic. So from that perspective, all polymer mags are exactly the same.
The truth of the matter is that the AR is long overdue for a series of upgrades, and redesigning a magwell built around a polymer mag built from the ground up is probably top on that list.
The only thing I've noticed with polymer mags is that if you leave them loaded for a long time, like months to a year, they will bulge, and the stack can kind of spread and jam up.
As noted above I had a couple of FDE PMAG 30 loaded for 11 years and I did not observe any problems. I used the provided storage covers. How does this bulge manifest?
As noted above I had a couple of FDE PMAG 30 loaded for 11 years and I did not observe any problems. I used the provided storage covers. How does this bulge manifest?
I use storage covers if they're provided, but so far magpul is the only one I know of that has them.
As far as how it manifests, the mag body just kind of stretches out over time, allowing the cartridge stack to spread out a little bit, which causes it to bind up. This happens as a result of trying to load the mag on a closed bolt. And like I said, if it happens it's easily cured by slamming the mag on its butt.
It is worth noting though that you should take the time to lock the bolt back before seating a mag, and this will prevent malfunctions.
Captains1911
12-04-20, 20:39
The only thing I've noticed with polymer mags is that if you leave them loaded for a long time, like months to a year, they will bulge, and the stack can kind of spread and jam up. The only problem this has caused me is trying to load a mag on a closed bolt. If the mag has bulged and you try to slam it on home, it gets jammed up and won't seat because the stack shifts and binds up in there somehow. If that happens, all you have to do is slam the mag down on its butt and the rounds will right themselves.
Because of discovering that issue, I have switched to metal mags. I only use Okay Industries GI mags with the tan follower. They are hard to find, but they do come up from time to time as Colt branded mags (which are actually just rebranded Okay mags). The bulging issue combined with the possible feedlip issue has just really turned me off of polymer AR mags.
Sorry, but I call BS. If this were an issue, than the ones I’ve had loaded for over 12 years would have almost certainly exhibited this.
Sorry, but I call BS. If this were an issue, than the ones I’ve had loaded for over 12 years would have almost certainly exhibited this.
I mean it's not something you're going to really notice because nobody ever loads on a closed bolt. I'm not really sure how I first noticed it. Laziness I guess.
tanksoldier
12-04-20, 23:52
I mean it's not something you're going to really notice because nobody ever loads on a closed bolt. I'm not really sure how I first noticed it. Laziness I guess.
Everybody that keeps a patrol rifle cruiser ready loads a mag onto a closed bolt.
That said, I find that my Colt LT6720R won't load a full PMAG onto a closed bolt. I have to use the old Vietnam trick of downloading to 28 rounds... but it has nothing to do with the magazine bulging.
Everybody that keeps a patrol rifle cruiser ready loads a mag onto a closed bolt.
That said, I find that my Colt LT6720R won't load a full PMAG onto a closed bolt. I have to use the old Vietnam trick of downloading to 28 rounds... but it has nothing to do with the magazine bulging.
I always load 28 rounds. All the mags I've tested only had 28 rounds loaded.
So why are these people loading on a closed bolt? Why not keep the bolt locked back?
So why are these people loading on a closed bolt? Why not keep the bolt locked back?
Not at a square range, deciding to reload a partially used magazine with a full magazine when the opportunity presents itself, so the bolt is still forward with a round in the chamber...
:rolleyes:
LMT Shooter
12-05-20, 07:28
I always load 28 rounds. All the mags I've tested only had 28 rounds loaded.
So why are these people loading on a closed bolt? Why not keep the bolt locked back?
"Patrol ready" is where you have the weapon on safe, bolt in battery on an empty chamber, with a magazine locked in the mag well. Storing the rifle in this condition is a very, very common LE policy. That's a lot of people who load on a closed bolt.
"Patrol ready" is where you have the weapon on safe, bolt in battery on an empty chamber, with a magazine locked in the mag well. Storing the rifle in this condition is a very, very common LE policy. That's a lot of people who load on a closed bolt.
Okay but they're probably softly seating them, vs. jamming them up in there like you would under stress.
tanksoldier
12-05-20, 14:20
So why are these people loading on a closed bolt? Why not keep the bolt locked back?
...because that's the definition of cruiser ready.
You've never seen an AR bolt close when it's bumped on the ground?
In a cruiser, with loaded mag inserted and bolt open, you risk chambering a round every time you hit a bump.
Okay but they're probably softly seating them, vs. jamming them up in there like you would under stress.
So you don't know WHY people do it, but now you're an expert on HOW they do it...
A piece of advice: never rely on the stress and excitement of a "for real" incident to HELP you accomplish something. Stress and adrenaline always make things harder, they never make something easier.
If you can't do it relaxed and stress free, you can't do it under fire.
...because that's the definition of cruiser ready.
You've never seen an AR bolt close when it's bumped on the ground?
In a cruiser, with loaded mag inserted and bolt open, you risk chambering a round every time you hit a bump.
So you don't know WHY people do it, but now you're an expert on HOW they do it...
A piece of advice: never rely on the stress and excitement of a "for real" incident to HELP you accomplish something. Stress and adrenaline always make things harder, they never make something easier.
If you can't do it relaxed and stress free, you can't do it under fire.
I seem to have accidentally run over a sacred cow here...
ViniVidivici
12-05-20, 21:09
No sacred cow, you just seem to be the only one of us who's had the problem.
All mags, rifle and pistol, are loaded all the time, except for a few designated and marked as training mags.
THOSE are the ones that get loaded/unloaded/shot through alot.
I mean it's not something you're going to really notice because nobody ever loads on a closed bolt.
I insert loaded magazines under closed bolts 10:1 over open bolts. Probably much more than that. Most owners will perform far more administrative handling tasks with their guns than shooting tasks.
There are magazines that when loaded with 30rds will seat under a closed bolt with relative ease when done deliberately. However, there aren't really any that I expect to do this across the brand/sku, and then across expected guns in the field, consistently. This includes ARCs, pmags, DDs, Lancers, and the many aluminums. Tolerances vary and stack. It's not an issue of quality, but compatibility.
Polymer mags wear, but I've not observed swelling issues as described. I have seen various fractures and wear as the companies played with their polymer formulations and people abused them, but swelling was not an issue.
tanksoldier
12-05-20, 23:11
I seem to have accidentally run over a sacred cow here...
Nope, just talked about things you don't seem to have much personal experience with.
No sacred cow, you just seem to be the only one of us who's had the problem.
All mags, rifle and pistol, are loaded all the time, except for a few designated and marked as training mags.
THOSE are the ones that get loaded/unloaded/shot through alot.
That doesn't surprise me. I'm just one of those people who notices things like that. I imagine it's happened to a lot of people and they probably just tapped the mag and reseated it and didn't give it a second thought. Me on the other hand, I always have to find out why. I loaded up a bunch of different polymer mags and left them sitting. Sure enough, after about a month of being loaded I was able to induce that same malfunction more often than not. I've now had them loaded for over a year now. Next time I check them I'll have to try and catch it on video.
For what it's worth, I don't think it's a major problem. The risk over metal mags is if you had a malfunction and cleared it, then went to insert the mag on a closed bolt and it wouldn't seat. I've never had a round fail to chamber or anything, and haven't had any problems seating the mags on an open bolt.
What's actually happening is if you seat the mag too quickly on an open bolt, it just puts too much pressure on the walls of the mag body, which bulges out, and that allows the cartridge stack to spread, which for some reason binds it up. Like I said, I'll try and get it on video.
Rifleman_04
12-06-20, 07:06
Sorry, but I call BS. If this were an issue, than the ones IÂ’ve had loaded for over 12 years would have almost certainly exhibited this.
It was very much an issue. Magpul was replacing mags for customers a few years back(maybe more) for that issue. IÂ’m not sure if the Gen 3 mags still do it but ALL of my Gen 1/2/MOE mags do it. DoesnÂ’t matter if they are downloaded or not so I keep mine topped to 30.
No sacred cow, you just seem to be the only one of us who's had the problem.
No. There was a pretty lengthy thread about it on this forum back in the day.
Oh and I keep my magazines (even polymer) loaded to full capacity all of the time. They do get cycled through every year or two though.
It was very much an issue. Magpul was replacing mags for customers a few years back(maybe more) for that issue. IÂ’m not sure if the Gen 3 mags still do it but ALL of my Gen 1/2/MOE mags do it. DoesnÂ’t matter if they are downloaded or not so I keep mine topped to 30.
No. There was a pretty lengthy thread about it on this forum back in the day.
Oh and I keep my magazines (even polymer) loaded to full capacity all of the time. They do get cycled through every year or two though.
I have a bunch of Magpul Gen2 unopened that I keep as spares, that being said, I keep my mags loaded at 28 rounds, this includes DH, Surefeed, Lancer and Magpul.... Some mags are 10yrs old some are 3 months old...Just personal preference
One of my Lancers is tight to close with 28 rounds on a closed bolt. If I slam it in, no issues. I tried 2 or 4 different mags same round count with no issue....that mag will go to range use.
Fully loaded... even the straight 20 round PMAG in the gun doesn’t have an issue when I remove it prior to practice. No so called bulge.
I keep two G2 PMAGs (all of mine are G2, except the few 40s I have in storage) with XM193 underneath the rear seat of my truck, just in case I ever needed another 60 rounds. Those are the only two magazines that get those dust covers put on them... because they are the only ones not protected from the environment. In the gun, safe. In my plate carrier, bullets down, safe. Underneath my back seat, where my girlfriend’s 8 year old daughter eats McDonald’s and other messy s***... something is going to find its way into it.
It was very much an issue. Magpul was replacing mags for customers a few years back(maybe more) for that issue. IÂ’m not sure if the Gen 3 mags still do it but ALL of my Gen 1/2/MOE mags do it. DoesnÂ’t matter if they are downloaded or not so I keep mine topped to 30.
Is there a statement from Magpul about this?
Just my observation but PMAGs have an issue with the 2nd round from the top “walking up” towards the first round and making it very hard to seat. I haven’t seen this issue with my D&H mags which leads me to believe there is a difference in the geometry of the feedlots that allows this on the PMAGs. I actually find D&H to seat very easy, sometimes more so than PMAG’s.
I also load all my mags to 30...as they were designed to do.
I agree with a couple things stated above: loading on a closed bolt is far more common when taking administrative tasks into account. And there are likely tolerance stacking issues from one mag to another.
Glock9mm1990
12-06-20, 11:05
Just my observation but PMAGs have an issue with the 2nd round from the top “walking up” towards the first round and making it very hard to seat. I haven’t seen this issue with my D&H mags which leads me to believe there is a difference in the geometry of the feedlots that allows this on the PMAGs. I actually find D&H to seat very easy, sometimes more so than PMAG’s.
I also load all my mags to 30...as they were designed to do.
I agree with a couple things stated above: loading on a closed bolt is far more common when taking administrative tasks into account. And there are likely tolerance stacking issues from one mag to another.
I’ve seen this with Gen 2 Pmags, Gen 3 doesn’t have that issue at least with my own experience YMMV
Rifleman_04
12-06-20, 11:13
Is there a statement from Magpul about this?
I believe Duane Liptak from Magpul addressed the issue in that old thread.
I believe Duane Liptak from Magpul addressed the issue in that old thread.
Thanks. Are you thinking of this or another?
Gents,
The smart folks here say this was a small batch issue with some earlier MREVs, and was corrected as soon as it cropped up. Was an internal dimensioning and clearance issue. If anyone has PMAGs that do this, contact customer service, and they'll swap you out 1 for 1 with new PMAGs complete with that new PMAG smell.
I’ve seen this with Gen 2 Pmags, Gen 3 doesn’t have that issue at least with my own experience YMMV
I still have it happen with Gen 3's. Some mags seem to have it worse than others, probably going back to that tolerance stacking thing...
Rifleman_04
12-06-20, 12:31
Thanks. Are you thinking of this or another?
https://www.m4carbine.net/showthread.php?179083-Ammo-PMAGs-and-long-term-storage&highlight=Pmag+top+round+transposed
Not to stir the pot, but I seem to recall MAC having a couple of issues with PMAGs that had been stored loaded for a very long time, like multiple years.
I looked back though his channel briefly and didn't see the video, so this is just coming off my admittedly shoddy memory. I believe they were Gen 2 mags that had been stored loaded with no covers in place. It wasn't a spring issue but rather something at the top of the mag either weakened or cracked and was inducing malfunctions. I believe he stated no issues with and mags he had stored with the covers in place.
It was very much an issue. Magpul was replacing mags for customers a few years back(maybe more) for that issue. IÂ’m not sure if the Gen 3 mags still do it but ALL of my Gen 1/2/MOE mags do it. DoesnÂ’t matter if they are downloaded or not so I keep mine topped to 30.
No. There was a pretty lengthy thread about it on this forum back in the day.
Oh and I keep my magazines (even polymer) loaded to full capacity all of the time. They do get cycled through every year or two though.
Good to know. I was starting to doubt my sanity there for a minute.:lol:
Glock9mm1990
12-07-20, 16:10
Not to stir the pot, but I seem to recall MAC having a couple of issues with PMAGs that had been stored loaded for a very long time, like multiple years.
I looked back though his channel briefly and didn't see the video, so this is just coming off my admittedly shoddy memory. I believe they were Gen 2 mags that had been stored loaded with no covers in place. It wasn't a spring issue but rather something at the top of the mag either weakened or cracked and was inducing malfunctions. I believe he stated no issues with and mags he had stored with the covers in place.
Thing is once you seat on a closed bolt, the bottom of the BCG pushes down on the rounds off the feedlips much like the covers do. Do it with a window pmag and you’ll see. I don’t know what MAC’s issue was.
Mysteryman
12-13-20, 16:49
Not to stir the pot, but I seem to recall MAC having a couple of issues with PMAGs that had been stored loaded for a very long time, like multiple years.
I looked back though his channel briefly and didn't see the video, so this is just coming off my admittedly shoddy memory. I believe they were Gen 2 mags that had been stored loaded with no covers in place. It wasn't a spring issue but rather something at the top of the mag either weakened or cracked and was inducing malfunctions. I believe he stated no issues with and mags he had stored with the covers in place.
Not to stir the pot, but the covers are not needed for storage.
MA2_Navy_Veteran
12-13-20, 18:47
I've only ever had a problem with long term loaded mags once - with two fairly new Ber.92 mags & a standard USGI 30 round mag were determined to have weakened springs after having been left loaded in the trunk of a parked car for @ a month in July, in the Tampa, Fl area. Interior temps of the parked vehicle were estimated to be over 280+ dergrees during the day & @ 82 or so degrees at night. Repeated hot/cold cycles (especially ones on the higher temp side of things) CAN cause compressed springs to take a set over time, just as repeated loading & unloading them can. Since then, I've been sure to never leave any of my loaded mags in the trunk of my vehicles, and have not had any issues with weak springs in long-term loaded mags. Just my experience here in central Florida.
I've only ever had a problem with long term loaded mags once - with two fairly new Ber.92 mags & a standard USGI 30 round mag were determined to have weakened springs after having been left loaded in the trunk of a parked car for @ a month in July, in the Tampa, Fl area. Interior temps of the parked vehicle were estimated to be over 280+ dergrees during the day & @ 82 or so degrees at night. Repeated hot/cold cycles (especially ones on the higher temp side of things) CAN cause compressed springs to take a set over time, just as repeated loading & unloading them can. Since then, I've been sure to never leave any of my loaded mags in the trunk of my vehicles, and have not had any issues with weak springs in long-term loaded mags. Just my experience here in central Florida.
Interesting! Thanks for the data point. That's a good thing to keep in mind that I hadn't considered.
I’ve seen this with Gen 2 Pmags, Gen 3 doesn’t have that issue at least with my own experience YMMV
Gen3 did it worse than Gen2 until they added aome nubs inside the feedlips in early 2016.
I had problems with it and send a few sets of mags back to Magpul and talked with them quite a bit about it. I tried some of the first mags with the revision and they seemed fixed.
tacticaldesire
12-17-20, 11:50
Not to stir the pot, but I seem to recall MAC having a couple of issues with PMAGs that had been stored loaded for a very long time, like multiple years.
MAC Seems to have problems with literally everything he touches.
davidjinks
12-17-20, 12:07
I have “Go” boxes with 12 loaded USGI mags each and a full reload on stripper clips. Every time a range trip happens, I will ask my kids to pick a number between 1-3 and then 1-12. Whatever numbers they pick, I grab 1 mag from the corresponding box and take it to the range and shoot it cold.
These magazines were loaded in 2005, put in .50 cal cans with descant packs. I have never had a single problem with any of the magazines I have tested. I will occasionally take 3 magazines from each box and check feed lips compared to bran new magazines that have never been loaded. Zero feed lip separation has ever been detected.
Howdy,
Pre-2020 I'd shoot at least once a month if not weekly so mags got rotated and used frequently.
With ammo shortage I'm not shooting my AR as much.
Most of my mags are PMags and assume they can be fine for months like this...or am I wrong?
I'm not in a position, at the moment, where I need 10 mags loaded; but there they sit waiting for another ammo score! I figure I best not shoot more than I can replace at least 50% of and it's been hard to find more than 40 rounds at a time it seems...No where within 100 miles had any last loop through the gun shops...
Thanks!
03Infantry415
01-08-21, 15:05
I have a few cans that I keep Magpul AR and Glock oem mags in. I check feed lips and the spring pressure once in a while. It's the constant use that will wear out the mags. Load them and store them you'll be fine.
Straight Shooter
01-08-21, 19:21
I documented this here one time...cant remember the exact year, but around 2008 or so, I shot two loaded 1911 mags, that had been loaded since I THINK it was 1936 or so, cant remember. I shot them out of an 1911 made in 1917 and used & carried in WW1.
We filmed it and all- both mags & ammo fired without a hitch.
A couple years ago- I fired two mags from a S&W 3906 that my dad had loaded back in the late eighties and put in a drawer and never touched again. They too, fired without fail.
Mags..and ammo too..last a hella long time.
I documented this here at the time...cant remember the exact year, but around 2008 or so, I shot two loaded 1911 mags, that had been loaded since I THINK it was 1936 or so, cant remember. I shot them out of an 1911 made in 1917 and used & carrid in WW1.
We filmed it and all- both mags & ammo fired without a hitch.
Damn ...
Straight Shooter
01-08-21, 20:57
Damn ...
Thats what WE said too. :)
Was a great experiance...I remember the 1911 shot several feet low for some reason we couldnt determine.
Actually, magazine spring life is not as simple as "load and leave - they will last forever", or "cycling is the only thing that wears out magazine springs".
In 1966 the Army did a five year study on this very subject. A report entitled "Evaluation of Pretreatment Process and Long Term Storage on Magazine Springs" was published with the results of this test.
There were two objectives, 1) determine the effect of various pretreatments on spring life and 2) determine the effects of long term storage of magazines stored at normal, hot, and cold temperatures. The parts we are concerned with are the life of a "normal" spring, as none of the pretreatments yielded cost effective improvements, if any improvement was seen at all, and the results of extended storage of fully loaded magazines versus unloaded magazines over 5 years of storage.
(Data from "Evaluation of Pretreatment Processes and Long Term Storage on Magazine Springs".)
LONG TERM STORAGE:
In order for the "spring to not take a permanent set in service" the spring must never be loaded beyond specifications, which is generally not more than 50% of the free length. Most magazine designs have the springs over-compressed when loaded to maximum capacity. M16 magazines are such springs, when fully loaded, they are compressed to 14% of their free length (18% if you only go to 28 rounds).
The magazines, some loaded and some unloaded, were stored for 5 years, at set intervals a portion of the springs were removed from storage and had the free length and load-at-length measured, the ones removed from storage did not return to storage after testing. After approximately, 12 weeks the loaded springs had free lengths reduced below the original value, and lost strength, around 84% specification value. After 24 weeks, the load-at-length values were 76% there original value.
From 24 week the loaded springs showed a very slight decrease in both length and strength, dropping to about 72% after 2 years and stabilizing at that value after that. After 1-1/2 years, in the loaded condition, spring exhibited an average set of 11% below the initial free length. This stabilized for the rest of the test period.
This indicates that the strain on the spring has an effect on the loss of strength and length, but if the strain is constant the reduction reaches a stabilization point, and how low that point is depend on the initial strain. Unloaded magazines also showed a decrease in free length and load-at-length values, but stabilized in 24 weeks just inside the acceptable drawing limits.
The functional testing of the magazine after storage was to fire all of the loaded rounds in them and see if there were any magazine attributable malfunctions, there were none.
So, you do loose a measurable portion of your spring strength after long term storage, but it will stabilize after approximately 2 years. A spring with a strength of 72% of its new specification strength does not adversely effect function, but it has some impact on total life, as we know cycling of the spring will also lead to loss of free length and strength.
SPRING LIFE:
Spring were gymnasticated at a rate of 116 strokes per minute between the assembled height (unloaded length) and the maximum design compression (fully loaded length), with the free length and load-at-length checked a set intervals. This cycle rate was considered a bit excessive, but as the in service cycle rates would be slower this was the "worse-case". By 1655 cycles, about 1/3 of the springs' load-at-length value had dropped below the new spring limit, and by 12,000 cycles, all of the springs had dropped below 50% load-at-length (which is probably insufficient for proper function), or had become so distorted cycling was impossible.
DISCUSSION:
The service limit is not necessarily the same as the production limit, and according to this study, a spring with 72% of the production limit is capable of providing adequate performance. However, it would be incorrect to say that long term storage of fully loaded magazines "has no effect on the spring". On average it took about 700 to 1000 cycles to reduce the spring strength values from "new" to 72%, so that much spring life has been lost. So, it depends on how often you load and unload your magazine, as to which is better for the life of the spring, storing loaded, or loading and unloading.
The up-shot is: It doesn't make any noticeable difference as to the question of "Which is better for a spring, loaded or unloaded?"
EDIT: If you want to know when your spring is near the end of its life, when unloaded, the force need to depress the second round in the magazine should not be less than 2.5 pounds, preferably closer to 3 pounds.
Mysteryman
01-18-21, 22:23
Actually, magazine spring life is not as simple as "load and leave - they will last forever", or "cycling is the only thing that wears out magazine springs".
In 1966 the Army did a five year study on this very subject. A report entitled "Evaluation of Pretreatment Process and Long Term Storage on Magazine Springs" was published with the results of this test.
There were two objectives, 1) determine the effect of various pretreatments on spring life and 2) determine the effects of long term storage of magazines stored at normal, hot, and cold temperatures. The parts we are concerned with are the life of a "normal" spring, as none of the pretreatments yielded cost effective improvements, if any improvement was seen at all, and the results of extended storage of fully loaded magazines versus unloaded magazines over 5 years of storage.
(Data from "Evaluation of Pretreatment Processes and Long Term Storage on Magazine Springs".)
LONG TERM STORAGE:
In order for the "spring to not take a permanent set in service" the spring must never be loaded beyond specifications, which is generally not more than 50% of the free length. Most magazine designs have the springs over-compressed when loaded to maximum capacity. M16 magazines are such springs, when fully loaded, they are compressed to 14% of their free length (18% if you only go to 28 rounds).
The magazines, some loaded and some unloaded, were stored for 5 years, at set intervals a portion of the springs were removed from storage and had the free length and load-at-length measured, the ones removed from storage did not return to storage after testing. After approximately, 12 weeks the loaded springs had free lengths reduced below the original value, and lost strength, around 84% specification value. After 24 weeks, the load-at-length values were 76% there original value.
From 24 week the loaded springs showed a very slight decrease in both length and strength, dropping to about 72% after 2 years and stabilizing at that value after that. After 1-1/2 years, in the loaded condition, spring exhibited an average set of 11% below the initial free length. This stabilized for the rest of the test period.
This indicates that the strain on the spring has an effect on the loss of strength and length, but if the strain is constant the reduction reaches a stabilization point, and how low that point is depend on the initial strain. Unloaded magazines also showed a decrease in free length and load-at-length values, but stabilized in 24 weeks just inside the acceptable drawing limits.
The functional testing of the magazine after storage was to fire all of the loaded rounds in them and see if there were any magazine attributable malfunctions, there were none.
So, you do loose a measurable portion of your spring strength after long term storage, but it will stabilize after approximately 2 years. A spring with a strength of 72% of its new specification strength does not adversely effect function, but it has some impact on total life, as we know cycling of the spring will also lead to loss of free length and strength.
SPRING LIFE:
Spring were gymnasticated at a rate of 116 strokes per minute between the assembled height (unloaded length) and the maximum design compression (fully loaded length), with the free length and load-at-length checked a set intervals. This cycle rate was considered a bit excessive, but as the in service cycle rates would be slower this was the "worse-case". By 1655 cycles, about 1/3 of the springs' load-at-length value had dropped below the new spring limit, and by 12,000 cycles, all of the springs had dropped below 50% load-at-length (which is probably insufficient for proper function), or had become so distorted cycling was impossible.
DISCUSSION:
The service limit is not necessarily the same as the production limit, and according to this study, a spring with 72% of the production limit is capable of providing adequate performance. However, it would be incorrect to say that long term storage of fully loaded magazines "has no effect on the spring". On average it took about 700 to 1000 cycles to reduce the spring strength values from "new" to 72%, so that much spring life has been lost. So, it depends on how often you load and unload your magazine, as to which is better for the life of the spring, storing loaded, or loading and unloading.
The up-shot is: It doesn't make any noticeable difference as to the question of "Which is better for a spring, loaded or unloaded?"
EDIT: If you want to know when your spring is near the end of its life, when unloaded, the force need to depress the second round in the magazine should not be less than 2.5 pounds, preferably closer to 3 pounds.
Not calling you or anyone out, but your data is nearly 50 plus years old. Technology, steel, and manufacturing processes have changed a lot.
Not calling you or anyone out, but your data is nearly 50 plus years old. Technology, steel, and manufacturing processes have changed a lot.
Have the laws of physics been amended to change the behavior of steel recently?
Most M16/AR magazine spring are made from the same type of material they were 50 years ago. If fact almost all magazine springs are made from the same two or three grades of steel.
Yes, there are newer materials out there, but guess what, They are all variations of steel, and they behave the same, just to different degrees. There are piles of research on that, too.
Interesting study. Might not be the worst idea to change out loaded mags and put them back on the shelf from time to time.
But the repeated cycling still points me to the idea that the mag body would fail from normal wear based on the round count involved in achieving the cycles that would yield significant spring weakening.
Interesting study. Might not be the worst idea to change out loaded mags and put them back on the shelf from time to time.
Just shoot in rotation, if for no other reason to keep the ammunition new. So if, in a pinch and you need to use all 53 of your preloaded magazines the ammunition won't be ten years old.
Colt Carson
01-19-21, 23:29
Have the laws of physics been amended to change the behavior of steel recently?
Most M16/AR magazine spring are made from the same type of material they were 50 years ago. If fact almost all magazine springs are made from the same two or three grades of steel.
Yes, there are newer materials out there, but guess what, They are all variations of steel, and they behave the same, just to different degrees. There are piles of research on that, too.
Serious question... Fifty years ago were they stress relieving, heat treating, shot peening or cryogenic treating springs?
99cobra2881
01-20-21, 09:17
People worry about magazine springs while the hammer spring in their AR15 is under tension 24/7-365.
Very few people store their AR with the hammer dropped. I don’t.
Serious question... Fifty years ago were they stress relieving, heat treating, shot peening or cryogenic treating springs?
Yeah. It does improve magazine spring life, but not by leaps and bounds, more like inches.
Cost analysis by the Army found it wasn't it wasn't worth it. Just replacing the springs a little earlier is cheaper in the long run.
People worry about magazine springs while the hammer spring in their AR15 is under tension 24/7-365.
Very few people store their AR with the hammer dropped. I don’t.
They take a set over time as well. If you look at old hammer springs you'll see the angle between the closed end and the free legs is about 170 degrees. With a new spring the angle is 180 degrees.
grizzlyblake
01-20-21, 09:56
So did I screw up by loading 90 D&H mags to 29rds last week for storage?
Just shoot in rotation, if for no other reason to keep the ammunition new. So if, in a pinch and you need to use all 53 of your preloaded magazines the ammunition won't be ten years old.
Is something wrong with then year old ammunition?
https://www.m4carbine.net/showthread.php?227102-Old-Ammo-How-Old-is-Too-Old
Glock9mm1990
01-20-21, 11:08
So did I screw up by loading 90 D&H mags to 29rds last week for storage?
I wouldn’t sweat it.
Colt Carson
01-20-21, 16:07
So did I screw up by loading 90 D&H mags to 29rds last week for storage?
Wolff Gunsprings claims a magazine loaded for a long period of time does fatigue the spring to some degree. Why would you store your ammunition this way? I couldn’t imagine needing more than a couple loaded magazines, or at most a few. Wolff does say downloading by one or two rounds does reduce spring fatigue.
Is something wrong with then year old ammunition?
https://www.m4carbine.net/showthread.php?227102-Old-Ammo-How-Old-is-Too-Old
Depends on how it is stored. Hot, humid conditions are not ammunition's friend.
So did I screw up by loading 90 D&H mags to 29rds last week for storage?
I don’t think it’ll bother anything but that’s kinda weird unless you’re getting ready for a machine gun shoot or something.
I generally have a loaded mag in the ARs I keep ready to use and a few spares loaded.
I keep a set of 5 training mags that are numbered that I use at the range.
I don’t keep the whole stash of my mags loaded because they’re just extras in the event that I have to replace one or something.
grizzlyblake
01-21-21, 08:43
I don’t think it’ll bother anything but that’s kinda weird unless you’re getting ready for a machine gun shoot or something.
I generally have a loaded mag in the ARs I keep ready to use and a few spares loaded.
I keep a set of 5 training mags that are numbered that I use at the range.
I don’t keep the whole stash of my mags loaded because they’re just extras in the event that I have to replace one or something.
Just cleaning and organizing the house after the holidays. I was able to consolidate my gun stuff by loading up the mags and putting them in FAT50 ammo cans that stack nicely inside my safe. 28 mags in each can.
The idea is that I'll give my two sons one can each with their AR in a few years when they're old enough to shoot.
I only did it because I've read so many times on here and other places that it's totally fine with quality USGI mags, especially downloading one round, to leave loaded for many years.
The_War_Wagon
01-21-21, 08:55
I couldn’t imagine needing more than a couple loaded magazines, or at most a few.
MOST people couldn't... until yesterday.
https://i.ibb.co/Fbp7BZh/idea.jpg
If you live in a big city, you just MIGHT have HUNDREDS of loaded magazines, at the ready...
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