Dirty gun = Pressure issues?

[greyghostnw]

do you trim your brass? Do you push your shoulder back properly? Make sure your brass is trimmed within .002 of each other 10-15 thousandths less than max in chamber. Have you taken fire control apart like plungers out as well sized brass till bolt handle just has a slight touch before it falls to bottom? Should measure around .002 less than fired case. If your not full length sizing at all its harder on your brass and bolt lugs and can create hard bolt lift. The list goes on. Case base swells if you let it get away…. Consistent redundant practice equals results on paper. Good luck.

 

[General RE LEE]

Filthy cans dropping chunks of carbon in a bore when bumped at the range or field will spike pressure.

I clean my Banish Backcountry ~ 300 rounds and I like to run a few Hoppes patches every other range trip. I also brush out the chamber every few hundred rounds to get the carbon ring.

I seldom go after copper unless there is a consistent change in groupings.

 

[Neilbob]

Bumping this thread just because the same thing happened to me the other day. During load workup for a new 7MM Sherman Short barrel, I worked up to pressure (slight ejector mark and a little sticky bolt lift) with N555 and 175 grain ELDX using virgin ADG brass. I figured I'd gain a slight amount of case capacity once fired, but I still dropped 0.5 grains and shot a few more groups that didn't show any pressure signs. Thought I was good to go and loaded up quite a few. Then after a few range trips, I got significant ejector mark and difficult bolt lift. I cleaned the gun, backed down another 0.5 grains, and also seated the bullet another 0.01 off the lands. I was already 0.030 off. Everything seems happier, but I'll keep an eye on it.