How much is to much firing pin protrusion

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Flip
.243 Winchester
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How much is to much firing pin protrusion

Post by Flip »

As the title states how much is to much.

I've been going through the last batch of 17 rem empties from my brother and have noticed that the primers look like they have been hit Hard in that the firing pin dent is very deep and the primer itself is dished inwards. There is the odd primer with a pin hole and I found a couple that are missing the entire disc out of the firing pin dent. I have not measured how deep they are or the rifle bolt face with the pin out need to go see him.

They are rem 7 1/2 primes. They are not a hot load of AR2208.

This the same rifle that we have had a couple of issues with. It pierced a primer with a mild load when I was working up a load for it

This may answer why it seems very easy to pierce primers with it.


Flip
chris.tyne
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Re: How much is to much firing pin protrusion

Post by chris.tyne »

Might pay to check that the shoulders are not being pushed back to far as well.....................................ment to add that around 0.050 to 0.060 protrusion would be fine.
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Flip
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Re: How much is to much firing pin protrusion

Post by Flip »

Cheers chris
morerams
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Re: How much is to much firing pin protrusion

Post by morerams »

Once you have had a few pierced primers the problem tends to get worse through both gas erosion of the firing pin and the hole in the bolt face and from weakening of the firing pin spring.
50 to 55 thou protrusion is normally enough to make the rifle fire properly as long as the headspace is correct.
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Glenn
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Re: How much is to much firing pin protrusion

Post by Glenn »

What action make is it Flip?

I built a Sako L461 17 Fireball that was doing it from the first shot!
I found out my neck thickness was all over the place due to my shity necking turning technique.
I went back through and redid them all again and all good!

I checked the firing pin protrusion and it was 68 thou!
Bit long so I shortened it to 52 after a Google search.

I changed to CCI BR4 primers for there harder cup.

I fired 15 shots to check it and shoot it in.
Works good.

I have not used it since, dose not float my boat!

Make sure you take the bolt apart.
I had little round bits of primer come out after I took the firing pin out.

Glenn
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Flip
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Re: How much is to much firing pin protrusion

Post by Flip »

itsa rem 700
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