Where did I see that?
I saw a post where a guy explains how to slit the neck of an unprimed case, insert your desired bullet, chamber the round and use the shell to determine the exact COAL for your gun.
Does this ring any bells? I'd like to read this again, and save it for my notes.
9mm, 40S&W, 45ACP, 45 Colt, 38 Special, .357 Magnum, 38 S&W, .243, & 30-06
CHL ~ Texas