I'm fitting the 45/70 barrel to last nights receiver.
Headspace and everything else is perfect ...except the shelf. The latch is all the way up. No rattle but I have to raise the shelf some.
The more I look at it, the more it looks like there i no way to measure for the shim. I'm guesing at about .009 but that' just a guess. Anyone who's done one want to give it a try.