Quote:
Originally Posted by 260 Rem
Iclund - no reason to think the firing pin hole has opened up on this BAT action. I am going to change brass and check over a chrony.
|
Looking more closely at the picture it could be possible that the pressure, on the primer, was not enough to push it back against the bolt face. This would allow the primer to flow around the firing pin by roughly as much as the primer was seated into the pocket. You could check this by measuring the primers seating depth near the rounded outside diameter with your calipers. Where it has flowed out would likely be 0.000" seat depth. Normally primers seat 0.005" into a properly uniformed primer pocket.
I don't think changing brass will help unless the primer pockets are larger which may allow primers to move back more freely. The most likely cause of this is that the Batt action has a stronger firing pin than necessary for the pressure you are running. This does not mean that the pressures are not fairly high as low pressures are usually indicated by a cratered primer. Measuring the 0.200" base datum with a micrometer, looking for the largest reading, on a new case and comparing it to a fired one may give you an indication of low pressure but the chronograph reading against a known pressure load would be the best.
Let us know how what you find.