03-12-2020, 11:06 PM
Kswhitetails Wrote:Klem, I've found the same exact things you list here. You are correct, the bullet does act as a mandrel, but they are much softer than a mandrel. I haven't gone the mandrel route yet, that's next. I'd expect that the mandrel would be more consistent, but wonder if it's actually worth the extra step considering I load for auto loaders. Time and testing will tell, but in reality it's a fifty dollar test.
It is worth it. I switched to a Porter Machine mandrel and I can use any conceivable size mandrel down to .0002. In other words, you can neck size for gas guns as well as bolt guns and choose any size mandrel you want. I run .002" of interference for bolt actions and .0032" of interference for gas guns. I anneal every firing and the brass comes out identical with +/-.0005 of runout at the case mouth.