Gunsmithing Firing Pin Assembly Problem? FIXED!

[Blanman]

So I'm pretty sure I have a problem and I was hoping you guys could help me out real quick. I've been having a lot of issues lately with what I thought were possibly "dud" primers from a bad lot but now after discovering my firing pin was only dropping about half of what it should be it worries me.

I measured how much my buddies regular old Rem 700 firing pin dropped, and it fell about .23ish I think, which is the amount that they're supposed to go apparently. Mine only fell about .17" and you an visibly tell that it didn't go as far. Here's a photo of the tang fully fired, but you can clearly see it still has room to go. Sorry for the crappy quality, it's all I had at the moment

Stiller Tac-30 action with Timney trigger, if that makes a difference..

 

[230grRN]

Re: Firing Pin Assembly Problem?

You should check your firing pin protrusion. It should be .050 minimum .055-.060 would be best. The cocking piece doesn't actually bottom out in the cocking cam recess, there will and should always be some gap there, altough yours looks like a little bit more than normal, but its hard to know without having it in from of me. The shoulder on the firing pin bottoms out in the bolt body and this is what sets your pin protrusion on the Remingtons and there clones. Its also what gives you the gap you see.

Also you should disassemble and clean the bolt body and pin thoroughly to make sure something hasn't worked its way in there and is causing your problem, its doubtful but possible.

The trigger could also be causing your problem, if there is insuffient overtravel which can cause the the cocking piece to drag on the trigger, which will cause the same issue.

 

[McCrazy]

Re: Firing Pin Assembly Problem?

Looks to me like your firing pin assembly was removed from your bolt and not re-installed correctly. That is a significant gap between the bolt body and the shroud that surrounds the end of the firing pin assembly. Can you screw it in another full rotation?

 

[Jkob60]

Re: Firing Pin Assembly Problem?

I needs to be turned in another turn. Turn it in as far as it will go then back it off just enough so it will set in the notch Just after the cocking notch.

 

[Blanman]

Re: Firing Pin Assembly Problem?

It won't go in another full turn, already tried. Checking the firing pin protrusion is my next step since I've already cleaned out the bolt body, there wasn't anything in there, that I could tell anyway. I would suspect the trigger also, but it does this when I fire it in my hand also, so there isn't anything for it to rub on to stop it when it's falling...

 

[Blanman]

Re: Firing Pin Assembly Problem?

ok it's definitely something with the bolt body. I fired it with the assembly removed from the bolt and it fired all the way down as it should. As soon as I screw it back in, it only goes halfway again. I've looked in the bolt body and see no debris, that I can discern anyway since I'm no gunsmith...I'm perplexed

 

[DAVETOOLEY]

Re: Firing Pin Assembly Problem?

How long have you owned this action? Any pierced primers?

I know you've cleaned it but it sounds like debris inside the bolt body. Flush with brake cleaner and blow out. Put a small amount of oil inside and blow out again to leave a light film on the inside.

 

[Blanman]

Re: Firing Pin Assembly Problem?

Nope, no pierced primers at all. I run standard factory loads in 6.5 Creedmoor which are very moderate loads. Action has around almost 3000 rounds on it, I can look for the exact number if you want. And that's what I did when I cleaned it, pulled out the assembly, flushed the inside with brake cleaner a few times, reapplied grease on the threads.

 

[DAVETOOLEY]

Re: Firing Pin Assembly Problem?

In the half fired position can you tap on the bolt and the pin fall.

 

[Blanman]

Re: Firing Pin Assembly Problem?

negative

 

[jeepwilson]

Re: Firing Pin Assembly Problem?

I had the same thing happen in my bench gun but I had pieced some primers and there was a piece of primer in my bolt body keeping it from protruding all the way.I would take the bolt apart and take a flat head screw driver and scrape down in the bolt body just to make sure that nothing is stuck in there.Then look at the collar on your firing pin and make sure no build up is there keeping it from going in all the way.I have chucked them up in the lathe and actually took a little off the collar to give more protrusion but this needs to be the last resort.

 

[Blanman]

Re: Firing Pin Assembly Problem?

Problem solved gents! pulled the firing pin spring out to find that the shaft that screws into the firing pin shoulder had backed out, so I just screwed it back in, put it back together and what do you know, everything is where it should be! Now to find some loctite...

Have to thank 230grRN for helping me with taking the spring out, never would've found that problem if I didn't pull it!

 

[230grRN]

Re: Firing Pin Assembly Problem?

Awesome! Glad it turned out to be something simple. See if you can get your hands on some Loctite retaining compound its just awesome for stuff like this.

 

[Blanman]

Re: Firing Pin Assembly Problem?

Already loctited it back on. Confirmed that it's fixed this morning by firing off all the "duds" with no issues. Thanks!