Quote Originally Posted by JeffreyDeGraff View Post
Rimmed cases stretch upon firing, just like rimless and belted cases. When you fire it, the brass stretches to fill the chamber, thus the term “ fire forming”. If your rifle has a very sloppy oversized chamber you will get more stretch, or if the headspace is off, you will get excessive stretching.


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Should I just size the shoulder back a few thousandths by backing my sizing die off? I'm probably overworking my brass by full length resizing. Using Lee pacesetter dies.

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