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Old February 27, 2011, 09:16 AM   #5
Walt Sherrill
Senior Member
 
Join Date: February 15, 1999
Location: Winston-Salem, NC USA
Posts: 6,348
This discussion pops up about every month here on the firing line. I've got a little document I paste in when I see the question asked.

A lot of people will tell you their experiences -- which will generally be based on one type of gun and magazine, and make generalizations based on that experience. Those are good experiences, but they may not be typical.

Guys who shoot 1911s, for example, almost never have to replace mag springs. Folks in the states with 10-round limits on mags, seldom change mag springs for many of their guns. But folks who shoot high-capacity race guns in competition, may change them a lot.

Last year I sold a Kahr P9 with eight mags, mags I had gotten from the original user. The mag springs simply died, almost overnight -- the gun just wouldn't feed. It had worked fine a few weeks before i sold it, the last time I shot it.

The buyer returned the gun, got his money back. He didn't trust the gun. I bought new springs, and the gun was suddenly running 100% again, and I later sold it for more. The springs in Kahr P9 mags are stiff, and they're hard to install. They have to do a lot to push 7 and 8 rounds in such a small gun. The prior owner must have left some of them fully loaded -- I never did.

There are springs and there are springs. It depends on how they were designed, and what they were intended to do.

Someone cited car springs. While I never put my car up on blocks, I've had suspension springs (both coil and leaf) that had to be replaced -- they DO wear out. But I don't think I've ever heard of tappet springs (the ones that are used with intake and exhaust valves) having to be replaced except as part of a major overhaul.)

Here's a link to a in-depth discussion of the topic here on The Firing Line. Be sure to read all the way to the end. One of the participants is a mechanical engineer who did a bit of research on the topic, and cited a number of sources. This seems to be the best presentation I've seen, and the most technically complete and correct. It's based on a good bit research and isn't based on one shooters limited experience with his or her guns. The author of the most informative parts is a member here who goes by the name Bernieb90. I think it's response #41.

The question was about "stretching springs" to rejuvenate them, but the discussion led to a much wider exploration.

http://thefiringline.com/forums/show...ht=spring+life

Put simply -- if a mag spring is pushed to it's design limits, spring life can be shortened. For many gun springs and mag springs, leavings mags fully loaded simply won't make a difference. But, for the mag springs in 16-18 round 9mm mags, hi-cap mags in .40s and .45s, or springs for some of the sub-compact guns, keeping them fully loaded CAN make a difference.

Recoil springs in some of the subcompact 1911s and other small guns have to be replaced far more frequently than recoil springs in full size guns. Many of the newest guns use springs in ways that they weren't used in years past, and springs are now a disposable/renewable resource -- something that wasn't the case in the old days.

Rotating mags doesn't prolong spring life -- it simply spreads the wear. Springs don't heal from non-use. They don't deteriorate if they're not overstressed. Stretching springs may cause them to fail, although one participants in the discussion swears that is NOT the case.

I've seen this deterioration in a number of guns and mags I've owned and used. I've got other mags (a bunch of 10 rounders for IDPA competition, and 7-rounders, back when I messed with 1911s) that I'm sure will never fail, being of good steel from reputable sources-- and never being overstressed.

(My CZ mags, for example, use the same springs in both the 10-round versions and 16-round versions. The mag tubes are physically similar, but in the high cap version, that "same" spring must do a lot more work and be compressed a lot farther. Any wonder that hi-cap mags might wear out a bit more quickly?)

Check the Wolff Springs FAQ area, too.

Last edited by Walt Sherrill; February 27, 2011 at 09:24 AM.
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