Blown Primers

Yesterday I had a nice experience. My 26.0 Varget 69gr Nosler load blew three out of five primers. No problems with this load a week before and no other signs of pressure. Round edges were still evident on primers and extraction was super easy with no bright spots on case heads. I was using CCI400s and in the past I have had a tiny blown pinhole in the center of the primer strike with those primers on occasion, but nothing like this....................It completely sheared the entire diameter of the firing pin strike out leaving the anvil in plain view. Interesting, to me at least. Guess I'll switch over to my Rem. 7-1/2s. I hate that because I have always found the CCI400s to shoot more accurately.

Have you checked the firing pin protrusion?

While setting up one of my rifles I set it a little to deep and it pierced a few before I set it to the correct depth. Afterwards it will not pierce a primer even with hotter loads. I too prefer the CCI 400's but have changed over to 7.5's because of availability, hopefully I don't have accuracy fall off because of it.

Dolomite

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Originally Posted by dolomite_supafly

Have you checked the firing pin protrusion?

While setting up one of my rifles I set it a little to deep and it pierced a few before I set it to the correct depth. Afterwards it will not pierce a primer even with hotter loads. I too prefer the CCI 400's but have changed over to 7.5's because of availability, hopefully I don't have accuracy fall off because of it.

Dolomite

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It was 0.045". I set it to 0.035" to see what happens. Hopefully no misfires.

Keep your protrusion around .041 and make sure your firing pin has a nice radius to it and no sharp edges. Try the CCI 450's or BR4's as they have a thicker cup diameter than the 400's and are able to take slightly higher pressures.

I have a 22-250 12FV that started this same problem. I did several things and it has stopped. The first thing is I scrubbed the barrel with a 20 cal. brush with enough 0000 steel wool wrapped on it to make it snug and dipped in Kroil. Second I took the bolt apart and rounded the firing pin with Crocus cloth and set it too .032
and this has seemed to take care of it, the firing pin had a little ridge that you could not see while it was in the bolt body.

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Originally Posted by Budweiser360

Keep your protrusion around .041 and make sure your firing pin has a nice radius to it and no sharp edges. Try the CCI 450's or BR4's as they have a thicker cup diameter than the 400's and are able to take slightly higher pressures.

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Ditto. The end of your firing pin should look like the ball at the writing end of a ball point pen. :)