Mag spring fatigue from keeping clips loaded?

[lilabner]

If a person is relying on an automatic as a home defense firearm, is there a problem with keeping a fully loaded clip in the pistol for long periods of time? Like weakening the mag spring? If there is, what is the solution? Loading clips only half full? Having two clips and rotating them periodically? I personally think a DA revolver is the best answer but not everyone owns one. I'm becoming an NRA firearms safety instructor so I need this information.

[corbanzo]

I keep a .40SW with a fully loaded (14 rounds) clip in it, havent noticed any problems.  I think I've always had the same clip loaded... and its been about two years since it's sat empty...  I'll take it out shooting, and then the same clip gets loaded afterwards, and I haven't noticed any fatigue in the spring, still a pain in the thumb (I need to get a speed loader)  But that is only a gun I've had for two years... many some of these other fellas have kept one loaded for longer than that?  I wouldn't want to keep it half loaded... because you just never know.

[Larry Gibson]

If a person is relying on an automatic as a home defense firearm, is there a problem with keeping a fully loaded clip in the pistol for long periods of time? Like weakening the mag spring? If there is, what is the solution? Loading clips only half full? Having two clips and rotating them periodically? I personally think a DA revolver is the best answer but not everyone owns one. I'm becoming an NRA firearms safety instructor so I need this information.

Depends on the quality of the springs. With good quality there is no problem. I have 3 Colt mags for my Combat Commander that have stayed loaded for 30+ years. I have two AMT .380 backup mags that have been loaded for 24 years. I also had several S&W M39/59 mags that stayed loaded for several years. I have 3 CZ75 mags that have been loaded for 10 years. I periodically shoot the above handguns to ensure functioning but mostly because I enjoy shooting them. None of the above exhibit any type of undue spring compression (note; all springs initiall take a "set" on compression)  or fail to function. I have seen several foriegn magazine and some US made magazine that will compress with time and cause feeding problems. M1 carbine magazines are notorious for this. I just returned from Iraq where all this units M16 and M9 magazines remained loaded for 12+ months without any problems. I also have 5 M14 magazines that have remained loaded for 30+ years without problems.

It pays to test any of them if they are for serious social purposes.

Larry Gibson

[Savage]

I am told by those who understant these things better than I, that spring fatigue occurs faster in a magazine that is loaded and unloaded frequently than in one kept under constant load. I shoot my duty mags dry every three months, and rotate the mags. Probably not necessary, and I have no problems leaving mags loaded for long periods of time, even years. The only mag springs I've had to replace were the ones I use frequently at matches.
Savage

[Chuck Buster]

If any spring get weak, stretch it out to the original length, then put it in a 400 degree oven for one hour. That will put the set back into it and temper it properly. When it comes out of the oven just let it cool to room temperature on its own; don’t forget to use a hot pad or you will have funny looking fingers for a while!

[Mainer]

I had horrible spring fatique problems with new factory 10 rnd magazines for a Glock 19.  They failed after being kept loaded for about a year.

[rockbilly]

:roll: Save your time and effort, 400 degrees in an oven for one hour is a shot in the dark at best.  There are many factors in "proper" heat treating a piece of metal.  First, one must know the exact metal specification, then know the temper desired to bring the spring to life.  In my experience, (22 years as a metal tech on aircraft) I have found the temperatures for treating a piece of metal for a spring to be much higher than the 400 degrees, and normally for a period much longer than one hour.  In most welding/heat treating shops, most materials are left in the oven to cool.

It is best to switch mags every few months, leaving them empty for a period so the metal can rest.

[257 roberts]

I never load my mags full And rotate all my mags every few months
Berreta 950, Colt Huntsman, Sig 225 Browning Hi- Power, Two Colts
Wilson mags.

[Savage]

Conclusions from my experience/readings:
1. Modern spring steel, properly heat treated, does not take a set from constant compression.
2. Numerous compression and decompression cycles will fatigue spring steel much faster than leaving the spring under constant load.

I have magazines that have been loaded for years. These are occasionally shot dry, reloaded, and stored. Haven't had any problems.
I stay away for the magazines of unknown orign, and have been satisified with the performance of:
Chip McCormic
Megar
Metalform
Wilson
American manufacture AR mags.
I have never had a bad AK mag, unless it had obvious physical damage.

If anyone is concerned about mag failiure, change the mag springs every year or so on duty/carry mags as a precaution. It won't break the bank!
Savage

[Sir Knight]

Modern spring steel, properly heat treated, does not take a set from constant compression.

The Wolfe Spring website will disagree with you on this point.

I keep mine loaded to 80% of capacity since that is what the military oiginally advised to do with the 20-round m16 mags.

[Mainer]

Sir Knight:  Interesting piece of info about military advice on M16 mags.

Can anyone tell us what the military currently advises with respect to high capacity handgun mags, e.g., the Beretta M9?

Do any major law enforcement agencies advise downloading high capacity handgun mags?

[lashlaruhe]

I asked this question at the SHOT show to Meg-Gar, S&W and CZ, all said to rotate every 90 days and let unloaded magazines rest.
Single stack magazine springs are able to remain loaded and not weaken much longer than the hi cap staggered magazine. Magazine springs are not that expensive and it would be better to change then out if they show any sign of weakness that to have one fail when needed. Remenber also that the military and police usually are not alone when confrontng a BG, however the rest of us don't have another person for backup when TSHTF and can fire until you could clear a malfunction.

[Savage]

The Wolfe Spring website will disagree with you on this point.

Not surprised. They sell springs, ya know. It can't hurt.

I keep mine loaded to 80% of capacity since that is what the military oiginally advised to do with the 20-round m16 mags.

Some of the original 20rd M-16 mags had feeding problems when loaded to capacity. The change to the new follower was an attempt to correct that problem.

My observations are based on my considerable real life experiences. Everyone has to be comfortable with their equipment, so I would suggest everyone do whatever they need to do.

Savage

[ed1921]

I read of a 1911 mag kept loaded since it was brought home after WWII that was fired recently with no problems.
That said I load my own down one round & don't worry about it as I have never had a problem.

[Sir Knight]

I had some bad experiences with some Para-Ordnance hi-cap mags and as a result, this is what I do.

First off,  I load all of my mags to 80% ...

6-round mag gets 5 rounds (6 x 0.8 = 4.8)
7-round mag gets 6 rounds (7 x 0.8 = 5.6)
8-round mag gets 6 rounds (8 x 0.8 = 6.4)
9-round mag gets 7 rounds (9 x 0.8 = 7.2)
10-round mag get 8 rounds (10 x 0.8 = 8)
11-round mag get 9 rounds (11 x 0.8 = 8.8)
etc.

Secondly, I alternate my mags every season (Mar 21, Jun 21, Sep 21 & Dec 21). I have two sets of mags. A set for Spring / Fall and another set for Summer / Winter. Right now the Spring set mags are loaded to 80% of capacity. On Jun 21, I'll empty them and load up the other set.

[kyote]

interesting topic.and a lot of good thoughts.and myself Like I guess some of you, have heard soooo many differnt reasons to do this are that are not to do anything at all.
one of you said yea,they sell springs,that is why they want you to replace them.(I think I got that half a-- correct)I think you hit the nail on the head there.as in the past they have stated thiers are the best and won't take a set like the others.
my fun guns I relpace ever so offten might be years.but my serious firearms for hunting and (hopefully never)defence.I normally change them out more offten.and try to remember to do in during "spring forward"but seems I have so much other stuff to do now that I have set up most yearly things with "spring forward" I have been getting laxs.
but if you carry a firearm for defence.are have one for the protection of your home,family and property.It would not be a bad idea to buy some new ones once in a while and install them(But,if you do that you must take them out and test for function and reliability,as the warrenty say they will replace if defective.and you have to be alive to get the repalcement). Brownells is a good source for the quality springs.I see midway has a full line now also.
and the military mags for the 16.most folks still today only load 16 to 18 rounds in the 20 rounders.new makes of springs and followers have made this not nessary.But old habits are hard to break when you have your life on the line.I always try for 21 at the range when blasting he he he..