Home Forums Reloading Big Game Rifles How can I get good necks?

The Starline brass comes new from the factory about eight thou under the SAAMI maximum spec and my used brass is fifteen thou under after several firings, resizings, and chamfering. Therefore, I am not inclined to trim it even shorter.

Could someone please explain how his brass is getting shorter than new after firing, sizing and chamfering several times. It’s got me puzzled as every piece of new brass I get is usually 10 thou under and then it lengthens. Somewhere something is definitely out of whack.

Brass starts out ok.
Brass gets shorter when fired.
Then it gets even longer than it started when full length reized.

If you want to fire brass 20 times with no trimming, look at the Lee collet neck die. But the brass will have to be segregated to one rifle.