Firing pin protrusion

[jacobhh]

I have a new firing pin I wish to install.

It needs to be shortened about .060 to meet
protrusion spec. Not having a lathe, I was thinking
of stoning it down. Would that work OK if I went
slow with it? Any advice etc.?

 

[rcmodel]

Firing pin for what?

Seems kind of unusual that a new firing pin would be .060" too long.


rcmodel

 

[gunsmithgirl]

I agree with RC. Double check your specs.

 

[jacobhh]

RC:

I was surprised also so I called Tubb in Texas. It's a Tubb Speedlock.
They ship it long expecting it to be turned down for a custom
fit to your bolt. That, IMHO, is unwise. Except for pin length
it's a drop-in. They tell you in the literature: 'must be installed by
a competent gunsmith' -in parentheses at the bottom of the
description. Although it's pretty obvious, someone might install
as is then go to the range and puncture primers.

The whole thing may be folly, but my follow-through gets shakey
after a few heavy loads so I thought I'd give it a try.

 

[rcmodel]

A Tubb Speed-lock for what?

If it's a round firing pin, like for a 700 Rem or something, you might be able to chuck it up in a drill press or handheld drill and stone the tip down.

The rounded contour on the end is VERY IMPORTANT, so try to copy the old firing pin tip as close as you can eyeball it.


rcmodel

 

[jacobhh]

Sorry RC. In my off-topic rant I forgot to answer the question.
It's an 8mm Mauser98, Changed a bit (bbl cut back behind the
counter-bore, Timney trigger and handgun scope on an S&K
mount.) The bolt & receiver are unaltered.

 

[Jim K]

Rcmodel is right, that is a good way to do that job. Just keep the firing pin top close to spherical and you will be OK.

BTW, it is rarely excessive firing pin protrusion that causes pierced (blanked) primers, as the firing pin simply stops in the primer. What causes blanked primers is a too light firing pin and/or a too weak firing pin spring. That means there is not enough firing pin momentum to resist the internal gas pressure, so the firing pin is pushed back into the bolt and a disc out of the primer follows.

Jim

 

[jacobhh]

Thanks guys. I'm going to do as advised, and I appreciate
the clarification on the primer issue, Jim.