Pierced primers - monitor your brass

[markm]

Bolt hole is right at .064". Both old and new firing pins pass the min/max protrusion gauge.

[Clint]

Bolt hole is right at .064". Both old and new firing pins pass the min/max protrusion gauge.

That FP hole doesn't look too round from the picture...

[tom12.7]

I agree wth Clint, at least by the picture provided. May be something to look deeper into.

[TXBK]

I noticed the same, but thought that it may be my eyes and/or device.

Markm, any idea of when that bolt was maufactured? Your pic shows 6 pierced primers. Is that all of the brass with pierced primers, or did you find more? Where would you put the chance that this was happening previously, and just hadn't been caught yet? Knowing how you reload, do you think you could have missed these signs on other pieces of brass? Surely, the bolt wouldn't erode without it being cause by the ammo, unless it was out of spec from the beginning. Right?

Honestly, I was going to be surprised if that was a BCM bolt, but I am not since you say it is...not.

[markm]

Well... The only reason I was looking super close was to sort off MEN brass in .223 which we happened to chrono last week. We clocked it at 40 plus FPS faster than our usual hodge podge mix of LC, etc.

I don't imagine it had been going on for much more than a few weeks... and with firing pin etching... i'd imagine it to be a snow ball effect.