CCI 400 SR Primers Flattening

[ohiogunnut]

Has anyone else read the threads on Brianenos and ARFCOM regarding CCI 400 SR primers flattening with moderate loads and heavy bullets? I have been working up a load for a 16" SPR build and settled on 24.4gr TAC under a 69gr Nosler which is max book load. Quickload shows just under max load as well, yet I am getting flat primers 10% of the time. Reading around on the net has shown several threads with people reporting this observation JUST with the standard CCI small rifle primers. I just loaded up 20 rounds using CCI 41 military primers with a harder cup to see if this is in fact the problem, but wanted to see if others here had encountered this. I checked headspace using go/no-go/field gauges and all is well there on the extension.

 

[wyobill]

Re: CCI 400 SR Primers Flattening

I had this happen with 25grs varget and 69 nosler,thicker cupped primers(br4) solved the problem.

 

[thespecialist]

Re: CCI 400 SR Primers Flattening

I get that with the 400's using 24.6gr of AA2230 under 55gr Nosler BT's. I switched to 450's because the #41's are non-existent around here and the problem went away.

 

[seanhagerty]

Re: CCI 400 SR Primers Flattening

I have been getting the same thing with 24.5gr of varget under 75 gr bthp's. I was just fixing to start using a lighter load because I was worried about the possible overpressure situation.

I will hold off and just pay attention to other pressure signs.

Thank you for bringing this up.

Sean