If you full length size them every time they might not last long. But they shouldn't be hard to chamber, if you're full length sizing. Are you neck sizing? I've been neck sizing only for my 338 Win. Mag., with a Lee collet die and I've loaded each case five or six times each now, but some are getting slightly hard to chamber. I have a Redding body die to bump the shoulders back next time I load up a batch.