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Firing pin specs

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14 November 2002, 06:08
<Jon B>
Firing pin specs
Are there any SAAMI specs on firing pin protusion and diameter? The rifle is a 1917 Enfield being converted to 416 Rigby. While I was converting it to cock-on-open, I noticed that the firing pin diameter was much larger than the one on my A-Square. Any help would be greatly appreciated.

Thanks

Jon
14 November 2002, 06:11
<JBelk>
The higher the pressure the smaller the pin......That's true down to about .070 dia.

Protrusion should be .060 plus or minus .005.
14 November 2002, 11:13
scot
The pin on the M1917 is larger diameter than the
P-14. You might have different model bolts in each rifle. Both work fine. I would not use a '14 pin in a '17 bolt though, the slop in the firing pin hole would be excessive. A '17 pin in a '14 bolt would not work at all.

I have no idea where A-square got their actions. I got a half a dozen P-14 drill rifles for $29.00 about 12 years ago. If I were them I would have stocked up. Maybe they did and hence used P-14 actions with the skinny firing pins?

[ 11-14-2002, 02:16: Message edited by: scot ]
14 November 2002, 11:32
partsman
I know my Sako in 375 H&H calls for it to protrude .050 and it has an adjustment for it on the back of the bolt. So I would keep it around that length myself.
14 November 2002, 15:08
John Ricks
I go for 0.055" minimum on a DGR and hedge towards 0.060", you never know what the headspace is on that box of Ammo you had to buy in some strange place. Misfires really start at around 0.050". Chamber up a belted chamber so the 0.220" go gauge lets the bolt close, throw in some 416 Rem RP brass with a 0.212" belt, combined with 0.050" firing pin protrusion, and guess what. Do the numbers, you have an efffective 0.042" firing pin protrusion, maybe less due to how tight the go gauge is. Hello hang fires and misfires. I have seen factory chambers that will swallow a no go gauge,makes the problem much worse.