Pistol primers and breech block damage?

[JKR]

My Shiloh has a definite dent around the firing pin hole. Is this caused by my testing with pistol primers a few years back, or is it normal wear?
I recently came into some Federal 150’s and I’m thinking I probably shouldn’t try them in the Shiloh. I did try them in the C Sharps but they’re pierced by the firing pin. It’s looking like pistol primers are a no go in my rifles.
JKR

[Don McDowell]

I think you would have to fire an awful lot of pistol primers to cause firing pin hole damage. I know a number of the big dogs that shoot nothing but rp pistol primers, and there are some that use various pistol primers , but they have modified the capping tool so that it will take a strip of paper and seat a thin wad under the pistol primer to "headspace" it .

[JKR]

I think you would have to fire an awful lot of pistol primers to cause firing pin hole damage. I know a number of the big dogs that shoot nothing but rp pistol primers, and there are some that use various pistol primers , but they have modified the capping tool so that it will take a strip of paper and seat a thin wad under the pistol primer to "headspace" it .

Yes. It’s hard for me to wrap my head around the idea that the primer slamming back .006” or so would have enough force to dent a steel block. And yet there’s a primer size, circular dent around the firing pin hole.
Jim

[Don McDowell]

I think most of my rifles have a primer impression on the block/bolt face, whether or not they have ever had a pistol primer fired in them or not.
I have a friend that has a modern day Freund conversion, it uses the original style one piece firing pin with the huge diameter for the Berdan size primers. He has to every time after firing, cock the hammer and drop it on the fired case before opening the action and extracting the case. If he doesn't do that after about 50 rounds the firing pin hole will get so full of brass shavings from the primer it starts giving erratic ignition like a broken firing pin.

[JKR]

I think most of my rifles have a primer impression on the block/bolt face, whether or not they have ever had a pistol primer fired in them or not.
I have a friend that has a modern day Freund conversion, it uses the original style one piece firing pin with the huge diameter for the Berdan size primers. He has to every time after firing, cock the hammer and drop it on the fired case before opening the action and extracting the case. If he doesn't do that after about 50 rounds the firing pin hole will get so full of brass shavings from the primer it starts giving erratic ignition like a broken firing pin.

Don,
By impression do you mean dent? Mine has an actual dent. If you hold a straight edge across it, you can see daylight under it. Perhaps this is a non issue. Also, I can’t be sure it was caused by pistol primers. I haven’t used very many in this rifle.
Jim

[Don McDowell]

I think it would take several thousand rounds of pistol primers to cause a dent in the breechblock.

[JKR]

Don,
Why do you think my C Sharps 74 pierce’s pistol primers? Is it the shape of the firing pin or the hammer spring taken from a Newhouse wolf trap?
No problem whatsoever with any LR primers.
Jim

[Don McDowell]

Most likely the softer primer cups, and the heavier mains spring.

[Don McDowell]

or is the firing pin spring broke, or firing pin channel dirty.

[JKR]

Thanks Don. I checked that out this morning. The firing pin spring, while not broken, was very weak. It could hardy be felt and barely moved the pin back when the hammer is lifted. I put in a much stiffer spring and fired it. It still pokes a hole in pistol primers so I’ll abandon that effort all together. I fired two primed but empty cases with LR primers and it worked normally. I’ll shoot it some this afternoon to make sure everything works as it should. I feel more comfortable with the stronger spring retracting the firing pin. The firing pin is scary small and weak looking. I’m going to make up a couple spares as I can foresee a problem coming!
Jim