I apologize for not being more clear. The case is tapered. If you slide it into a tapered female hole, like a taper ring gauge, without force and one goes in further than the other, then the capacity of the case will differ all other things considered equal. So my assertion was that if a case springs back more than another case then you really don't know what you have. Its random at best. The only way that measuring your cases means anything is if you compress the case into the body or full length sizer and check the volume held in a uniform position. Sometimes we get things in our head and it makes us feel better but it is often meaningless if you attempt to get it down to the nats rear. GGMM ammo is a perfect example of what matters. It really doesn't do anything except satisfy your need to be anal. BTDT 20 years ago.