Do Magazine Springs Suffer From Metal Creep?
BY Herschel Smith
5 years, 5 months ago
So there is yet another post about magazine springs and whether they should be replaced, and if so, when. This is in the same theme I wrote about several years ago when there was another little flurry of articles and posts about this. I’m going to cover this ground one time for everyone.
Metal creep is caused from slippage of crystalline structures along boundary planes, whether FFC, BCC, or whatever. One reader writes that “springs don’t wear out from compression.” This is along the same lines as most of the [mistaken and incorrect] articles I linked the last time I addressed this issue that claimed that stainless steel doesn’t creep below the yield limit.
Do you know any piano tuners? I do. Yea, they have to go back a few days later and retune because of metal creep. But most piano wires are carbon steel under high stress. What about stainless steel?
Do not make the claim that stainless steel (like SS304) doesn’t suffer creep below the yield limit and at low temperatures. Yes … it … does (“In all tests at applied stress/yield strength ratios above 0.73 some plastic deformation was recorded”).
No offense, but don’t try to be an engineer if you’re not one. If you make the claim that SS304 (I presume the material of most magazine springs) doesn’t suffer from metal creep, you’d be wrong, and then you’d also be answering the question the wrong way.
The right way to look at the question is one of whether the creep is significant. It usually isn’t, and it is less significant than for carbon steel. It’s also not significant for applied stress/yield strength ratios lower than what the authors tested. Where your specific magazine spring falls in this data set is best determined by the designer, not me (I don’t have drawings or any other design information).
Besides, for most readers, you aren’t loading 34+ magazines per day and putting 1000+ rounds downrange for 300+ days per year as a workup to deployment. For 99.99% of the world, this is a pedantic question. For those who do put that many rounds downrange and have to use the magazines bequeathed to you by predecessors who did the same thing for years, you will want to watch your feed and ensure that it’s smooth, consistent and reliable. If it’s not, then change the magazine springs (or get new magazines – there could be another issue). They’re cheap, and it’s no big deal.
Note: No warranty express or implied is included with this article. Nothing here constitutes formal engineering counsel – you have to pay to get that. Nothing here includes claims on any specific magazine spring, whether said spring is loaded to the right applied stress/yield strength ratio to cause deformation, or whether anyone reading this article needs to change magazine springs in any given situation.
On June 23, 2019 at 9:58 pm, BRVTVS said:
To my mind, this is one of the more sensible presentations on the topic. It mostly agrees with what you wrote. https://youtu.be/pch0J9-7i2k
On June 23, 2019 at 9:59 pm, Ratus said:
Magazines are wear items.
Get more.
On June 23, 2019 at 10:23 pm, Fred said:
“The right way to look at the question is one of whether the creep is significant.”
Rightly put. I should strive to be better at it myself because I do enjoy precision in language when I see it.
Also, is the argument I’ve read which states that a mag kept loaded (spring under constant pressure) will not lose it’s springiness as quickly as one used often and left empty when not in use. So, does frequent use (I realize the generality of this so let’s call it daily use) or constant load cause the creep to become significant first?
And, as long as a Republican is in the White House actually usurping your rights, instead of a Democrat not actually usurping your rights, you might as well just get whole mags and plenty of them since they are so cheap, while your rights ARE being usurped in fact by masterful stroke after masterful stroke of 3D chess, instead of how expensive they’ll be when a Democrat gets elected and NRA actually does something other than be a cheap suit, it being a fund raising and political action arm of the Republican Party and nothing else. Ugh. Implied scarcity is as good as the real thing. On wall street they call it the pump and dump. When it comes to gun rights, it’s the NRA hustle.
On June 24, 2019 at 12:00 am, Dan said:
Metallic creep is a NONISSUE for 99.999% of users. So is the “compression fatigue” subject. And for the tiny minority
that do put enough rounds through a mag to have to worry
about the issue there are OTHER issues to be dealt with such
as abuse of the feed lips….probably a much more likely cause
of failure than the spring. Regardless…..if you use your mags
a LOT….which the vast majority of gun owners do NOT do then
yes, regular replacement is important.
On June 24, 2019 at 5:35 pm, Gryphon said:
I keep numerous Magazines Loaded 24/7/365 for Every Magazine-Fed Weapon I have. A few get Used somewhat frequently at the “Backyard Range”, but a large number are kept in Reserve Ammo Cans, Marked with Loading Dates. I have every once in a while taken on of these and ‘Shot It’, and even ones now Loaded for 10 Years have suffered No Failure to Feeds.
I have to agree with those who believe that keeping a Spring under Tension is effectively Harmless, and “Metal Creep” is Insignificant in this situation. Wear and Tear on Mags used Everyday is much more likely to affect the Feed Lips and Body than the Springs.
FWIW, on my P-Mags that are kept Loaded, I put in 28 Rounds and top it with one of their Protective Covers, which pushes the Top Round out of Contact with the Feed Lips.
On June 25, 2019 at 11:56 am, Jay Dee said:
Hi Captain,
As a matter of fact I am an engineer who has been designing springs for the auto industry for now close to a half century.
Yes, springs do lose tension, lose load, creep, whatever. Many old automobiles require new suspension springs after a decade or so. Magazine springs, recoil springs & hammer/striker springs will lose load as well. Good quality well designed springs will last a long time but they will slowly lose tension.
A good example is my Colt Government Model Series 70. After 30 years, it just wasn’t working anymore. Springs are cheap. I replaced the recoil spring, the extractor and all the magazine springs. My 1911 now runs like new.
As a rule, I replace the recoil springs and magazine springs in my guns about every 10 years or so. If the gun is used a lot, I consider replacing the springs sooner; especially if you depend on it.