Thread: New barrel vs New rifle conundrum

Originally Posted by ebf

Ok, so a couple of questions.

Is the issue you are concerned about headspace ? Flat primers without heavy bolt lift is more a sign of headspace issues than pressure to me.

Or are you suddenly seeing MV changes ?

Are you full length sizing or neck sizing only ? Do a shoulder measurement of a fireformed case.

Repeat the test with your usual bench setup, preferably sturdy front and rear rests.

These were loads I worked up to, to see where my max load is. Lighter loads primers were fine.
The primers were not completely flat, but definitely flattening around the edge compared to lighter loads. .5 gr over ADI's max.
MV was going up each .5gr increment added.
I neck sized the brass so head space should be good.
Head space was done by my gunsmith when he re-reamed the chamber to 25-06 rem

It's just that I seem to be chasing my tail with the 25-06 rem. I can get a good group if I let the barrel cool completely and shoot off the bench, but even three quick shots they start to spread and the barrel is pretty hot. So as it has recently been pillar/glass bedded etc and no pinching of the action etc, I'm thinking that the old barrel is letting me down.
Where as my 303-25 seems to group with what ever I put down it. (it has a fairly new barrel)