Blown primers and other malfunction troubleshooting

[markm]

[mpom]

Believe the raised ridge surrounding the firing pin indent in the primers indicates a high pressure situation.

Mark

[markm]

Believe the raised ridge surrounding the firing pin indent in the primers indicates a high pressure situation.

Mark

I'll have to explore that idea.

[gaijin]

Yes. We always referred to that as “primer flow”, and it is produced by an overpressure situation.

[markm]

Yes. We always referred to that as “primer flow”, and it is produced by an overpressure situation.

The funny thing is with a Rem 700 factory bolt, I get primer flow with 308 sub sonics. Their firing pin holes are a little large.

[opngrnd]

The funny thing is with a Rem 700 factory bolt, I get primer flow with 308 sub sonics. Their firing pin holes are a little large.

I've also noticed this.

[1168]

The load that was light…were its primers cratered like that? You using VV data for 69gr Sierras? With which primers?

[gaijin]

The funny thing is with a Rem 700 factory bolt, I get primer flow with 308 sub sonics. Their firing pin holes are a little large.

Of course you’re correct. Oversized FP tunnel can cause that too.
Assumed that wasn’t the case with your AR.

[AndyLate]

I have heard of folks breaking bolt handles trying to hammer an action open, but have never seen someone twist the bolt body before. You gotta back off a grain or two

Andy

[markm]

Of course you’re correct. Oversized FP tunnel can cause that too.
Assumed that wasn’t the case with your AR.

We're just running too hot. Velocities don't really show it, but there's not doubt.