I didn't see you mention the headspace created when the thread "slop" is taken out; in this case (IIRC), .0015". This would have to be factored into your index markings.

KevinDon't all you guys lap the thread "slop" out? Like Virgil King and the guys at the Houston Warehouse. ;D

As Hammer said, this idea will only work if you swap between dedicated actions and barrels.

I use a very sharp punch to make an faint index mark, that way I can buff (grind) it out.

Bill