Mythbusters: Keeping magazines loaded long term


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HighVelocity
December 26, 2005, 05:34 PM
Back in the late 80's early 90's I was big into IPSC and was shooting a few thousand rounds a week of 200gr cast SWC 45acp ammo. Of course I had a pretty big pile of magazines as well.
Thirteen years later (last week), I'm digging through a drawer and find two Wilson Rogers 1911 mags loaded with my old reloads.
This morning my wife and I stood side by side on the firing line and emptied one mag each as fast as we could pull the triggers.
All 16 rounds went downrange without a hitch after being loaded for over 13 years! :eek:
These old Wilson mags saw very hard use back in the day so the springs were definitely used.
So is it ok to leave magazines loaded for years at a time? I'm thinking yes.

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jsalcedo
December 26, 2005, 06:12 PM
Good magazines can stay loaded for decades and still function properly.

There are many anecdotes of people shooting .45 auto mags that had been loaded for 50-60 years.

g56
December 26, 2005, 06:22 PM
The answer to the question depends on several factors, primarily the quality of the springs and the exact material they are made of. This was brought up recently in an article about the new magazines for AR's from Brownell's, they are available with stainless steel springs which are mil spec, or chrome silicon springs that aren't mil spec. There was a rep from the manufacturer on another board that answered some questions about the different springs, he stated that the mil spec stainless steel is more likely to take a "set" than the chrome silicon springs. Both are quality springs but there is a difference in performance, the mil spec magazine spring showing that the military has different priorities than some others, it appears the military specs stainless steel for corrosion resistance, but for personal use the chrome silicon might be the better choice.

In your case you were using a very high quality magazine that would certainly have high quality springs, but not everyone buys that quality of magazines, so it might be appropriate to say that "Your results may vary". :)

http://www.brownells.com/aspx/NS/Store/ProductDetail.aspx?p=21225

M2 Carbine
December 26, 2005, 06:41 PM
Good magazines can stay loaded for decades and still function properly.

There are many anecdotes of people shooting .45 auto mags that had been loaded for 50-60 years.

True. In the mid 60's I was given a 1911 magazine that had been loaded since WW1.
I emptied the magazine with my GI 1911A1. All the rounds fired and cleared the barrel but were very weak.
The magazine is mixed in with my other 45 mags and I have no idea which one it is.

JamisJockey
December 26, 2005, 07:07 PM
Good magazines can stay loaded for decades and still function properly.

There are many anecdotes of people shooting .45 auto mags that had been loaded for 50-60 years.


I'm one of those people. I've shot WWII ammo that's been loaded since the late 40's out of a 1911, about 40 rounds without a problem.

HankB
December 26, 2005, 07:23 PM
Both are quality springs but there is a difference in performance, the mil spec magazine spring showing that the military has different priorities than some others, it appears the military specs stainless steel for corrosion resistance, but for personal use the chrome silicon might be the better choice.
There have been numerous stories coming out of Iraq that the magazines supplied with the army's Beretta 9mm pistols are cr@p, primarily because of the SPRINGS which weaken to the point that they'll no longer push the rounds up.

The magazines are made by "Checkmate" rather than Beretta, apparently because "Checkmate" quoted a lower price in their bid. (Or maybe they were to be built in a select congressman's district?)

Certainly, priorities seem to be different . . . and I haven't heard of anyone going after the manufacturer because the specs weren't met. :rolleyes:

tbeb
December 26, 2005, 07:48 PM
I think single stack magazines like a 7-round 45 ACP magazine can be kept loaded for a long time. Not sure what a long time is, so I change mine once a year. Don't know for sure, but I don't keep double stack magazines like a 15-round 9mm loaded for a long time. I change magazines every 2 months. That's probably overkill, but that's my practice.

JohnKSa
December 26, 2005, 08:05 PM
Good quality single column magazines (particularly 1911 mags) do NOT have problems with being left loaded indefinitely.

The same is NOT true of many double column magazines. The springs can weaken noticeably in as little as a few weeks from being left fully loaded. Usually underloading by only one round will eliminate this problem.

Wllm. Legrand
December 26, 2005, 09:43 PM
The key is the QUALITY of the metal in the spring. Good springs will not deteriorate over time, but there is strong evidence of compression and expansion weakening springs. Of this I am unsure.

Nonetheless, In those MBRs that are kept with loaded mags I follow the SEAL practice of loading 18 in the 20 rd. mag. This seems prudent.

I have not experienced any mag spring weakening in any pistol I've owned for years. A more prevelant problem would be denting feed lips or changing feed lip geometry somewhat. That I HAVE experienced.

Art Eatman
December 26, 2005, 10:04 PM
The controlling factor is the quality of the steel. Any spring which takes a set without being bent past the yield point of the steel just "ain't much" for quality.

Think about the valve springs in cars. When the motor is shut off, some of the springs are compressed. Now think of cars in museums which fire right up after years, as long as the oil is okay and fresh gasolline is used. Even when the valve is closed, there is tension on the spring.

At a 500 rpm idle, a valve spring cycles just over four times per second. Multiply that by months of run-time before a valve job--and the springs, usually, aren't replaced...

Quality...

Art

Art

doubleaes2
December 26, 2005, 10:08 PM
Art, That was a great analogy. Do you mind if I keep it?

adam

poe_9999
December 26, 2005, 10:13 PM
i bought a used HK USP 45. The mag springs were shot. They would feed the ammo fine, they just weren't strong enough to push the slide stop up after the last round fire all the time.

Reno
December 26, 2005, 11:16 PM
Metal fatigue comes from repetetive loading, not holding a single load for some given amount of time (assuming it's under the yield point)

thebucket
December 26, 2005, 11:40 PM
When I did my M-16 qualification, the mags we were using were the oldest the Air Force, I think. The springs were so worn they failed at least once per round. In one round, I had a FTF 3 times with one mag. Fortunately, I'm pretty quick and managed to finish within the time limit, but I probably lost a couple of points because of it.

JohnKSa
December 27, 2005, 01:20 AM
CLEAR evidence that compression ALONE (without cycling) can weaken a high quality spring.

http://www.funsupply.com/airguns/cocktest.html

Note that ALL of the springs weakened. Note that the weakening was EASILY measured. Note that the weakening progressed the longer the springs were left compressed. I have seen results of similar tests which show identical results, therefore this is a reproducible test.

Furthermore, these are very high quality springs made of excellent materials which have been specially treated to minimize wear and breakage while maximizing spring life. These springs are basically the heart of airguns worth several hundred dollars--they are just about as good as they can be.

It is worth noting that the springs in these airguns are typically coil-bound when the airgun is cocked and the depth of compression can make a BIG difference in spring life. That is also an issue in double column magazines which often compress the spring to the coilbound state.

Basically EVERY authority on spring piston airguns will tell you that minimizing the amount of time the gun is left cocked (minimizing the amount of time the spring is left compressed) will maximize spring life. In fact, one of the prime selling points of the PCP airguns and gas spring airguns is that they can be left cocked indefinitely without fear of damage. Furthermore, it is generally agreed that SHOOTING spring piston airguns (cycling the spring) is not nearly as harmful as leaving them cocked.

AND, if you ask people for their personal experience, you won't have to look far to find someone who can verify that they have seen mag springs weaken from being left loaded--NOT just from cycling.

Here's an experiment: Post that you just bought some new double-column magazines and they are too hard to load. Within a few replies someone will tell you to load them fully and LEAVE them loaded to encourage the springs to weaken sufficiently to allow easy loading. You won't get anyone telling you to cycle the springs to weaken them.

Automobile valve springs are a poor analogy for magazine springs. They are extremely stiff springs--they have to be to stand up to the abuse they go through. Magazine springs could be made that strong and then they would never weaken significantly--but no one could load the magazines!

The factors that determine if leaving a spring compressed is going to weaken it are as follows:

Spring quality. (Self explanatory)
Depth of compression. (Compressing to fully coilbound often reduces life)
Spring design. (Sharp bends in the spring, insufficient thickness, etc.)

Any one of these factors can cause issues, combinations of factors make the problem even more pronounced.

Take a look at a typical single column mag spring and then look at a double column spring. The single column spring typically isn't compressed to the coilbound state with the mag loaded, and usually has smooth radiused bends. The double column mag spring is often completely coilbound when the mag is fully loaded. Also, double column mag springs often have sharper bends at the corners to fit the contours of the magazines.

CombatArmsUSAF
December 27, 2005, 02:14 AM
Bucket- I am a combat arms instrcutor and the problem you were having problably wasn't the spring. It is a combination of using training weapons with training magazines. I run the same magazines through my M4 Carbine without any problems, and that goes for all the cops (around 400) on my base shooting M4s also. Also, many of the malfunctions/stoppages I see on a daily basis on my range are caused by the operator, not the weapon or magazine. Just a little food for thought.

VirgilCaine
December 27, 2005, 10:40 AM
As was made abundantly clear to me elsewhere, springs don't wear out from normal use...just if you compress them past what they are designed for.

armoredman
December 27, 2005, 11:00 AM
There have been numerous stories coming out of Iraq that the magazines supplied with the army's Beretta 9mm pistols are cr@p, primarily because of the SPRINGS which weaken to the point that they'll no longer push the rounds up.

The magazines are made by "Checkmate" rather than Beretta, apparently because "Checkmate" quoted a lower price in their bid. (Or maybe they were to be built in a select congressman's district?)

Certainly, priorities seem to be different . . . and I haven't heard of anyone going after the manufacturer because the specs weren't met. :rolleyes:
Everyone of my staff that goes to Iraq, I reccomend that one item they take with them is three or four high quality Berreta mags, if they are allowed to do so.

Gimme.50
December 27, 2005, 11:11 AM
The magazines are made by "Checkmate" rather than Beretta, apparently because "Checkmate" quoted a lower price in their bid. (Or maybe they were to be built in a select congressman's district?)

Murphy's Laws of Combat
#15 Never forget that your weapon was made by the lowest bidder.

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