buckhorn_cortez, if you go through every round with a concentricity gage and tweak the bullets in the case until the round-to-round variation is under 0.001 - and you can see the difference in accuracy, you are probably the only person on this planet to do so with a .308 Win. cartridge.
And your worst groups with bullets having .002" to .003" runout would have to be no larger than 1/4 inch at 100 yards.
Nobody in the top levels of competitive shooting with the .308 Win. cartridge would suscribe to this premise.
Besides, if you're measuring bullet runout with the cartridge resting on the body right behind the shoulder for the gauge's front reference and the case body right in front of the extractor rim for the back reference, you are not measuring bullet runout relative to how the case neck and bullet aligns in the chamber. The case body right behind the shoulder ain't where the cartridge centers in the front of the chamber when it's fired.
US Navy Distinguished Marksman Badge 153
Former USA Palma Team Member
NRA High Power Long Range High Master
NRA Smallbore Prone Master
Last edited by Bart B.; December 21, 2012 at 06:32 PM.