Firing pin radius

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ab_bentley

Guest
Anyone have tips on replacing the radius on a firing pin?

I'm thinking form tool, unless there's a better method.
 
For centerfire high pressure rifles you want a flat with a small radius on the edge. That reduces the distance the primer can flow back around the tip. Small but significant.
 
Dave Tooley said:
For centerfire high pressure rifles you want a flat with a small radius on the edge. That reduces the distance the primer can flow back around the tip. Small but significant.
Click to expand...

So, are you saying, no radius with broken edge?
 
Back in the day, someone told me that a proper tip has two radii. A large one at the center and a tighter one at the edge. I think that you would want to do a little more than break the edge but not come back too far down the side. If you do, you will create space in the front of the hole for a crater. Having a radius on the edge of the hole also contributes to this "problem".
 
Dave Tooley said:
For centerfire high pressure rifles you want a flat with a small radius on the edge. That reduces the distance the primer can flow back around the tip. Small but significant.
Click to expand...

That's a great tip, Dave. I never thought of it that way.

Every Custom Action I own has a firing pin tip with a radiused end. What you said makes a lot of sense.
 
In Stuart Otteson's book THE BOLT ACTION, Vol. 1 he states, "...primer indention seldom exceeds about .020 in. " (page 279)

If this is true, it would seem that a firing pin tip that is radiused back no more than .020" to .025" from the very front would be perfect, and provide a nice seal around the firing pin hole.
This is what I try to achieve on actions I have made for myself, and it seems to work pretty well.

FWIW

Steve Kostanich
 
ab_bentley said:
Anyone have tips on replacing the radius on a firing pin?

I'm thinking form tool, unless there's a better method.
Click to expand...

LISSEN to Tooley

basically when it comes to bolt action rifles there's GOD, and about 6 other people.

Dave is one of those 6
 
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