Originally Posted by
bigcountry
Please don't see this as stepping on your toes. But I disagree. I have been down the partial FL sizing road quite a bit and came up not happy. Its ok if you have some gauges to see what your doing. See how much variance you are getting in your shoulder measurements. But one thing I found out is sometimes a die not cammed over can cause runout and shoulder measurements that are all over the place up to .010". If I go that route, I suggest folks by some lee collet dies or redding bushing dies and do it properly.
I know John Barshness is big on this, and I have debated it with him online before. Turns out he never knew what the shoulder length measurements were or the effect it has. He said he just keeps backing up until its tight to chamber. Might as well have a varying headspaced rifle IMO.
I wouldn't call it partial FL sizing, but maybe it really is. What I was trying to get at, and what happened to me, is don't over do the FL sizing. When I started out, I was doing exactly what Lee's directions stated. The brass loaded fine, shot fine, but after 3 or less firings, brass began to separate. I found out that I was sizing them way too much. When I finally got the tools to determine the amount I was sizing, I understood the problem that I was running into. Since then I have been carefully measuring the amount of sizing being done to my brass I am now on my 5th firing of my last 50 pcs. of brass for the 7mmRM.