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Do Springs Take a Set if the Striker is pre-cocked/the hammer cocked?
Posted: Tue Apr 07, 2020 11:56 am
by Crash
Will the striker spring on my S&W Shield or the hammer spring on my S&W EZ 9mm "take a set" if they are left pre-cocked/cocked for a long period of time (say 3 months). If this is the case, the I might want to leave the chamber empty and the striker/hammer uncocked.
What say ye?
Crash
Re: Do Springs Take a Set if the Striker is pre-cocked/the hammer cocked?
Posted: Tue Apr 07, 2020 12:27 pm
by bobby
Springs if made correctly IE Smith and Wesson does I do believe. Then it cycles that weaken the springs not compression. Also if the spring is over stressed ie pulled too far. then it will change tension. Poor heat treating in the past is where this comes from.
Re: Do Springs Take a Set if the Striker is pre-cocked/the hammer cocked?
Posted: Tue Apr 07, 2020 1:57 pm
by Crash
bobby wrote: ↑Tue Apr 07, 2020 12:27 pm
Springs if made correctly IE Smith and Wesson does I do believe. Then it cycles that weaken the springs not compression. Also if the spring is over stressed ie pulled too far. then it will change tension. Poor heat treating in the past is where this comes from.
bobby,
Thanks, appreciate the info--relieves my mind.
Crash
Re: Do Springs Take a Set if the Striker is pre-cocked/the hammer cocked?
Posted: Tue Apr 07, 2020 2:34 pm
by crazy2medic
My Paraordnance P14 is kept cocked and locked, I have had it since 1994, it still has the factory springs in it and it still goes BANG every time it's suppose too
Re: Do Springs Take a Set if the Striker is pre-cocked/the hammer cocked?
Posted: Tue Apr 07, 2020 5:12 pm
by oljames3
My 5 S&W magazines for my M&P9 M2.0 5inch stay loaded. The magazines cycle during practice and training. So, for the last 3 years, these magazines have been loaded and cycled.
Re: Do Springs Take a Set if the Striker is pre-cocked/the hammer cocked?
Posted: Tue Apr 07, 2020 5:29 pm
by Crash
crazy2medic wrote: ↑Tue Apr 07, 2020 2:34 pm
My Paraordnance P14 is kept cocked and locked, I have had it since 1994, it still has the factory springs in it and it still goes BANG every time it's suppose too
/quote]
crazy2medic,
Thanks for the info--doesn't sound like I have anything to worry about.
Crash
Re: Do Springs Take a Set if the Striker is pre-cocked/the hammer cocked?
Posted: Tue Apr 07, 2020 5:32 pm
by Crash
oljames3 wrote: ↑Tue Apr 07, 2020 5:12 pm
My 5 S&W magazines for my M&P9 M2.0 5inch stay loaded. The magazines cycle during practice and training. So, for the last 3 years, these magazines have been loaded and cycled.
oljames3,
Thanks, appreciate your input. From your and other folks' input, doesn't appear that I need to be concerned.
Crash
Re: Do Springs Take a Set if the Striker is pre-cocked/the hammer cocked?
Posted: Tue Apr 07, 2020 5:48 pm
by bbhack
There are alloys that "creep" when under constant elastic region stress. That means the molecules move around under stress, and would eventually lose springiness or break. I do not believe any steels do this.
Most any piece of metal has residual stresses. Some areas may be stress free, while others areas may be close to the elastic limit. While you think you're in the elastic region, some areas may be undergoing plastic deformation. This problem is not based on time with steels. Copper wire, if used to hang a mirror, will eventually break.
Re: Do Springs Take a Set if the Striker is pre-cocked/the hammer cocked?
Posted: Tue Apr 07, 2020 8:01 pm
by Texas_Blaze
All materials experience stress relaxation. This is the decay of stress with time. When there stress developed in the material due to deflection decays, the strain becomes permanent. When strain is permanent, then force of spring is deceased. We know this for example, is an issue in metal spring energized seals (what is that you ask?). These are used in downhole tools and have a service life of 10-20yrs. The rate of stress decay will depend on time and imposed load. So if designed properly, the spring can last the expected lifetime of the product.
Re: Do Springs Take a Set if the Striker is pre-cocked/the hammer cocked?
Posted: Tue Apr 07, 2020 8:33 pm
by bbhack
Texas_Blaze wrote: ↑Tue Apr 07, 2020 8:01 pm
All materials experience stress relaxation. This is the decay of stress with time. When there stress developed in the material due to deflection decays, the strain becomes permanent. When strain is permanent, then force of spring is deceased. We know this for example, is an issue in metal spring energized seals (what is that you ask?). These are used in downhole tools and have a service life of 10-20yrs. The rate of stress decay will depend on time and imposed load. So if designed properly, the spring can last the expected lifetime of the product.
https://www.nationalboard.org/Index.aspx?pageID=181
Look at Table 1 at the bottom. Below these temperature these materials do not creep.
Re: Do Springs Take a Set if the Striker is pre-cocked/the hammer cocked?
Posted: Tue Apr 07, 2020 8:57 pm
by Texas_Blaze
bbhack wrote: ↑Tue Apr 07, 2020 8:33 pm
Texas_Blaze wrote: ↑Tue Apr 07, 2020 8:01 pm
All materials experience stress relaxation. This is the decay of stress with time. When there stress developed in the material due to deflection decays, the strain becomes permanent. When strain is permanent, then force of spring is deceased. We know this for example, is an issue in metal spring energized seals (what is that you ask?). These are used in downhole tools and have a service life of 10-20yrs. The rate of stress decay will depend on time and imposed load. So if designed properly, the spring can last the expected lifetime of the product.
https://www.nationalboard.org/Index.aspx?pageID=181
Look at Table 1 at the bottom. Below these temperature these materials do not creep.
All materials creep. Even if it’s not significant for a given application. Even glass creeps. But whatever.
Re: Do Springs Take a Set if the Striker is pre-cocked/the hammer cocked?
Posted: Wed Apr 08, 2020 8:36 am
by oohrah
Metals, especially steel, do not creep. And as bbhack said, as long as the load is under the elastic limit, there is no permanent deformation, so barring corrosion or other outside influence, the spring will perform its function essentially forever.
Re: Do Springs Take a Set if the Striker is pre-cocked/the hammer cocked?
Posted: Wed Apr 08, 2020 10:06 am
by The Annoyed Man
In some firearms, things like firing pin springs, recoil springs, and magazine springs are considered to be "consumables" ... just like the timing belt or chain in a car, for instance. Heck, even gun barrels are consumables. (Read up on AR15 gas vent erosion for just one example of why.) However, most of these things will last through MANY thousands of more cycles than the average user will ever subject them to, so for all practical purposes, this is not something most of us will ever have to worry about for almost any gun built in the last 75 years or so.
I still have the original firing pin spring, recoil spring, and magazine springs in my dad's old 1943 Ithaca 1911A1 which he carried in WW2. They still work fine, and for the years from 1945 to his death in 1990 when I inherited that gun, it was kept uloaded, but the magazines had been stored loaded with FMJs. And to the best of my knowledge, Dad never fired a gun again after the war....having already had all of the gunfire he ever cared to experience again. So that was 45 YEARS of storage with the magazine springs under tension. These days, the mags are unloaded, and the pistol is mostly a safe queen. I bring her out once in a great while, but she’s earned her rest. But when I do bring her out, I still use the old WW2 magazines, and they function just fine.
Anyway, all of this was my long-winded way of repeating to the OP what others have said.... don’t worry about it.
Re: Do Springs Take a Set if the Striker is pre-cocked/the hammer cocked?
Posted: Wed Apr 08, 2020 11:23 am
by Lena
I have a magazine loaded by my uncle in WW1 I have shot 1 round a year from it for 3 years now and works fine. I change out my carry mags 1-2 times a year and don't give such a thought at all.