Bore out a standard Neck die to accept 0.500 Redding bushings.

Mark,

That's the problem I'm having with an 8 x 57 AI - the necks aren't gripping well after firing and sizing in a die made with the reamer. I suppose this could also indicate that I made the reamer neck on the large size. Might be back to the lathe. I'm glad shot-out Mauser barrels are plentiful and cheap.

Maybe an easy approach would be to ream-out an 8 x 57 collet neck sizing die? But this wouldn't be pure do-it-yourself. I think I'm going to have to make a roughing reamer!

Thanks for the info!