1891 argentine Mauser firing pin protrusion?

[swampcrawler]

Sitting here playing with my Argentine, and remembered that the one time I fired it, years ago, I had the following issue: load magazine, close bolt to chamber round, open bolt and eject live round, like round had firing pin mark on primer.

So I pulled out the bolt and got a measurement. With the cocking piece in the position it would be in if it had just fired and were still closed (sorry, I have no idea how to word this), protrusion is 0.056, which I believe is about right.

But with the bolt as it is when chamfering a new, live round, I'm getting 0.018 protrusion. This is letting the pin bump the primer as the round is chambered. Doesn't exactly give me warm fuzzy feelings.

So I took the bolt apart and screwed the....(Sear? The piece that screws into the back of the firing pin and engages the trigger sear piece to cock when closed) in one more rotation.

Now there is zero protrusion when chambering live round, but only 0.016 when "fired".

What's going on here?

 

[ironworkerwill]

That not supposed to happen. It needs surgery.

Edit * I guess I have selective reading second time tonight!
I bet it's just good and "broke in".
The FP always varies... probably from being dry fired 1.2X10^9 times.

If the firing pin is in a hard and fixed position when cocked, then it needs surgery.

It looks like you've surgically re adjusted your FP. Make sure it fires, I don't think . 016" is enough. When you get done fixen it, make sure it don't auto-readjust.

 

[swampcrawler]

I bet it's just good and "broke in".
The FP always varies... probably from being dry fired 1.2X10^9 times

I know I was responsible for at least half of those as a kid lol. Thanks for the reply. I'm just going to leave it be till I get some ammo, then ill dig into it again.

 

[ironworkerwill]

Ok, I just whipped out the Google foo. Apparently the FP cannot be adjusted by twisting in the firing pin( from what I just read, because I DONT KNOW for sure)

Alternative suggestion: field strip.... Again, make sure everything is snug, make sure it's clean, re-reassemble, re measure FP. But you probably did that already.

Nothing's like redoing stuff all over again.

 

[Steel Horse Rider]

I haven't taken any of my Argie's bolts apart but your action would represent a thread with a 25 threads per inch pitch. Did it look that fine?

 

[tark]

Before we go any further here, we need to know WHICH Argentine Mauser you are talking about ! I assume you have an 1891, not a 1909. If so, and you need any parts, I have a '91 with a bore so rusted it is totally useless as a firearm. I got it for free and you can have the parts for free, excepting the receiver. How about I send you a complete bolt assembly? It would probably fix your problem and will doubtless be OK on headspace. At the very least, you could unscrew the firing pin/ bolt shroud/ safety assembly and install it in your bolt to see if that fixes the problem

A lot of those South American countries attempted to prevent coup attempts by storing the rifles in one place and the breechbolts in another. I have a pristine 99% Chilean Mauser, with a mismatched bolt. Shoots fine. I have two 91s and either bolt will work fine in either rifle.

Shoot me a PM if you want any parts.

 

[tark]

Why do I always forget to look at the thread's subject? Idiot. So you do have a 91. Good. I might be able to help