Gunsmithing Force of Firing Pin Spring

[mdesign]

I have a factory 700P in 300WM and a custom built on a 700 LA with a Callahan firing pin assembly. When dry firing, I notice that the factory firing pin assembly falls much harder than the Callahan and the the primers are dented more than any rifle I have.

I would not really care but have started to notice how much more the gun shook when I was practicing my lessons from the on-line training class and wondered if too much force could effect accuracy.

Within reason, is there such a thing as too much spring force?

 

[BOLTRIPPER]

Re: Force of Firing Pin Spring

when you place the callahan in.....did you re-adjust the trigger ?

 

[mdesign]

Re: Force of Firing Pin Spring

Yes. I measured the amount of fall from the cocked to the fired position and they both travel .280 between positions but the one hit bottom with much more of an impact.

 

[BOLTRIPPER]

Re: Force of Firing Pin Spring

W H A T.......

accuracy is all about triggers and barrels...the light weight firing pin and stronger spring only get you a faster lock time...and the firing pin only go so far....the spring just sends it quicker....with this stronger spring....the let off on the sear is weighted different and must be adjusted....the only time you will see any benefit to the aftermarket spring/pin will be in positional shooting.

if you got cratered primers....its either a headspace issue or the loads are a bit warm ....or the powder is really temp sensitive creating higher pressures....

 

[427Cobra]

Re: Force of Firing Pin Spring

Or a big giant firing pin hole from Remington

 

[mdesign]

Re: Force of Firing Pin Spring

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mdesign</div><div class="ubbcode-body">Yes. I measured the amount of fall from the cocked to the fired position and they both travel .280 between positions but the one hit bottom with much more of an impact. </div></div>

Bolt...

What I mean is that, yes I adjusted the trigger. Both rifles have factory 700 triggers, same pull of 2.5 lbs with no over travel. Is there some other adjustment I am missing?

I also checked the amount that the firing pin falls as there is some differance in the cocking pieces. The firing pin on both guns travels .280 from the cocked position to the fired position but the factory spring hits with much more force. The gun shakes slightly during dryfire from the impact making me think it could effect accuracy just a little if you made any error in your gun handling.

I also was merely commenting that the primer is dented deeper on the factory spring that is hitting harder. They are not cratered from excessive pressure, etc. The pins fit very nice in the bolt body.

I guess my question was, can you have a spring that is too strong and it actually hurts your accuracy? My thinking being that as long as you have enough force to fire the primer everytime under the conditions of use a lot of extra force might not be good if it made the gun less accurate.

I have shot the rifle with the softer hitting spring in the snow and cold at temperatures far below zero and never had a problem.

 

[BOLTRIPPER]

Re: Force of Firing Pin Spring

I guess my question was, can you have a spring that is too strong and it actually hurts your accuracy? My thinking being that as long as you have enough force to fire the primer everytime under the conditions of use a lot of extra force might not be good if it made the gun less accurate.



.....no

a light wiff of oil to lube the pin/spring assembly is all that is needed.....AND in extreme cold...just a wipe down w/lubed rag will suffice...i have know of greased assemblies to not function in extreme cold at the most in-opportune moment....

 

[BLAWTON]

Re: Force of Firing Pin Spring

Actually you can have a spring that is to much. It will cause movement and can even change the seating depth of the bullet before the powder is ignited and catches up. The softest spring you can use and still get constant ignition will give a more consitent ignition. If your looking for a faster lock time because your firing in a position then you need it to try to reduce pulled shots....

 

[mdesign]

Re: Force of Firing Pin Spring

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: NotAGuru</div><div class="ubbcode-body">Actually you can have a spring that is to much. It will cause movement and can even change the seating depth of the bullet before the powder is ignited and catches up. The softest spring you can use and still get constant ignition will give a more consistent ignition..... </div></div>

I thought this might be the case but was not sure. I'm going to disassemble the bolts and compare the springs to see if there is an obvious difference.

It would be interesting to test to failure to see how little spring force it takes to have consistent ignition. You would have to allow a safety factor as you would not be able to test all conditions. I wonder if anyone has ever tried this. I suppose if the spring got too weak you could give up a lot of lock time.

Thinking about it further...one could go with the really strong spring and adjust the distance of firing pin travel. Maybe it only needs to fall .100 before it hits the primer instead of the .280 the standard cocking piece gives you on a Rem 700.

 

[BLAWTON]

Re: Force of Firing Pin Spring

You have to be careful about dropping your fall down too low. You will not have the force you need to get a consistent strike. The firing pin needs some travel to create the enough force. I use a 24 pound spring and have seen people use as low as 20 pound springs and have got very good results. Lock time doesnt mean much if your shooting well.

 

[former naval person]

Re: Force of Firing Pin Spring

Also check your firing pin protrusion. If you are getting deep indentations, the tip could be a bit long...asking for perforations.