Gunsmith Members

shortgrass

Well-Known Member
Joined
Mar 31, 2010
Messages
3,016
Location
Western Oklahoma
Nice depection and cut out. This is great, but how does the owner of the bolt nkow what is wrong unless they cut their bolt in half?? If you have some realtime examples of the bolt cut out splease show them, and then also show a bolt head where the firing pin hole is out of round. Would be a better presentation.
Thanks
Len
Cratered primers, like jgs8163 posted pics of, show that something is wrong. The pic I posted show what a good fix would look like. You don't have to section a bolt to know if you made a good fix, or not. Don't recall any mention of out of round firing pin holes in this thread. That doesn't mean that there are not a few out there. The issue is, the hole is bigger than it needs to be on some. I gaged a few RR bolts and the 3 I checked would except a .081" gage pin, but not a .082" gage pin. I'm not going to bother dis-assembling a bunch of bolts just so I can mic pin diameters and gage holes so I can post numbers here, but the one on my work bench measured .075". That's .006" clearance,, and .002"- .003" more than I have allowed on a bushing. But, 006" ain't too bad and primer cup flow probably won't be much of a problem. I have noticed a few RR bolts that have a chamfer on the firing pin hole, from the factory. There's a hole that needs bushed so the primer cup doesn't flow into that chamfer. Older, pre-RR actions/bolts are normally the ones that need attention, or if you change to a small diameter pin. Bushing a firing pin hole, be it for use with a small diameter pin or to close up the 'gap' and use the original diameter and prevent primer cup flow, is 'custom work', where 1 on 1 measurement is used. .003"- .004" clearance is plenty, as long as the pin is guided, like the pic I posted shows. The pin tip is not guided when it comes from the factory, that's why there's a bit larger hole for 'production tolerances'.
 
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shortgrass

Well-Known Member
Joined
Mar 31, 2010
Messages
3,016
Location
Western Oklahoma
Nice depection and cut out. This is great, but how does the owner of the bolt nkow what is wrong unless they cut their bolt in half?? If you have some realtime examples of the bolt cut out splease show them, and then also show a bolt head where the firing pin hole is out of round. Would be a better presentation.
Thanks
Len
Maybe you can post some pics of out of round firing pin holes, and some real time examples, which would give a better 'presentation'? I see you have Custom Chambering and Cerakoting in your signature, so you must do some custom work. I just don't have the time, as I don't want to fall behind on the work in my shop. I feel lucky just to have a bit of time to log-on here.
 

Muddyboots

Well-Known Member
LRH Team Member
Joined
Feb 7, 2013
Messages
2,210
Location
Michigan
Curious, JE (🙏) mentioned Holland oversized firing pin as possible solution. Has anyone actually tried the Holland oversized firing pin? Results?
 

milo-2

Well-Known Member
Joined
May 1, 2011
Messages
1,240
Location
Gillette, Wy
Curious, JE (🙏) mentioned Holland oversized firing pin as possible solution. Has anyone actually tried the Holland oversized firing pin? Results?
Not sure if mine was a Holland, but a local smith put an oversize firing pin in a Stiller bolt for me. I know he had to machine it down slightly, cured my problem of cratering and piercing primers in small primer Lapua brass.
 

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