Firing pin spring replacement ?

H

H."Snuffy"Smith

New member
Some of you “engineers” with factual info only please. #1 Will a cocked Panda bolt left out of the rifle lose it’s torque value (maybe not a good term ?) if stored over a period of time ? I usually leave the bolt out and store it in my rifle case….NOT GOOD ? Please relate some technical info on this. #2 Now , if I have a drill press and a flat bed postal weight scale and I put the end of the firing pin assembly into a tool socket and push the drill chuck down onto the end of the assy., will this give me correct data. I hear of some shooters replacing their springs annually…necessary ? Please relate your experience.

I do believe in the BR game, many things are done, that may seem overkill, I’m not so sure about this one.

A shooter recently told me that he had replaced a spring in a BAT action and it improved the accuracy of the rifle. Was this the ONLY thing that he did…I don’t know
 
Snuffy, springs do have some memory, meaning that a compressed spring will eventually weaken some. As to whether cocked or uncocked is the best way, I doubt if there is a difference since the spring is still under some load. But, uncocking can't hurt.

Each year at the Super Shoot I have Carl or Tom replace springs in 2 of my Pandas. The new springs are about 1/2" longer than the ones just removed. Checking the old springs and the new springs on a bathroom scale I can't really tell that much difference. I guess replacing the springs is a "just in case" thing. Besides, when the Super Shoot is going on Carl and Tom don't really have anything to do, yhea!
 
IF the spring

is designed properly and made properly then it should never need replaced. I have all my springs made at Sterling spring. Joe at Sterling runs calculations on all of the springs I have made. If the stress in any part of the spring exceeds yield, then it will tend to take a set or wear out/break over time. The factory Remington springs are barely over the yield limit. My springs are barely under the yield limt. All the small springs have lots of margin except the Sako plunger springs for the extractor. They all yield the first time they are installed. Joe hates the design, but it is an exact copy of the Sako. There are spring calculators online that you can plug in the OD, wire size, coils, length etc and they will tell you at what load they are yielding. It dont hurt to replace the spring for sure. Free length is not a good indicator if the new spring is stronger etc. IF your old spring gets shorter with time, it IS definately yielding and loosing force.

The scale measurement is correct and will give good data.
 
I made a couple of alum blocks that are marked "SA cocked length" and "LA cocked length" for checking Rem firing pin springs. Using the bathroom scale/drill press method, I tossed out all of them that were under 22# at cocked length. I ignore free length.
 
Jay - do you have any idea how long it takes your springs to drop in weight?
A couple of months ago I did a stupid little test with a new factory Remington spring. I've always heard the histerical warnings of springs "going bad" so I put one onder about 90% compression in a firing pin changing tool. After 2 weeks the free length went from 5.14 down to 4.96 a reduction of 3.5%. But after about 6 more weeks at 90% compression there has been no further reduction. Now - for sure I don't have the means to track the weight. It would be really interesting to see how the weight drops over time even with no more loss of length.
I figure in BR every little bit helps and new springs are cheap.
 
Here's some history that is factual; hopefully it'll help some:

I have 3 Panda actions, the oldest of which is from 1986, and the newest from 2000. I check the springs at least anually using a drill press & a digital scale, and none have gone anywhere near being under 20 lbs at cocked length.......My spare spring will sit there and last forever at the current rate of tension loss.

I do unscrew the striker assemblies over the winter and when a given gun isn't being shot very often. Interestingly, I bought the '86 action unfired in '95, and the bolt had been stored uncocked (no trigger) since it was new. The spring isn't any lighter than it was when I got it, nor is it much different than the other two.

-Dave-:)
 
Thanks ,guys...just something else.....

to be concerned about. Very good answers and I do appreciate it.

"Snuffy"

PS. Maybe if I live another SEVERAL years, I'll acquire some :) BR knowledge.
 
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