“Next, fired cases have expanded and shrunk back a thou or two from full chamber length. Meaning there's absolutely no need to size shoulders further back from the fired length.
Wncchester, I hear that a lot “Next, fired cases have expanded and shrunk back a thou or two from full chamber length....” I will extend a courtesy to you, ‘HOW?’ How is it possible?
Again, I check 30/06 chamber length for the M1917 with a 280 Remington case, I check 03 Springfield chamber length with a feeler gage only, both methods will indicate case shrinkage after firing.
I am not a fan of perpetuating a myth, goes with the myth, a case gets longer and or shorter when fired. No one measures before and again and they do not know where the shoulder was located in reference to the case head and they all believe the shoulder is bumped, and I ask how? When does bumping stop and forming starts?