I have a pretty pre-war Merkel double rifle from 1931. Has .318" bores. Shoots S&B 8x57JR very well.

For reloading, I'm using a RCBS 8x57JR FL die with a .318 expander plug (RCBS #56366). Sized necks are correct, but unloaded brass won't allow the rifle to fully close. I'm using a shellholder that I had on hand for 44-40 work. RCBS package says use #26. Is there any chance the recommended shell holder for this rimmed cartridge is thinner, measured from the where the base of the cartridge sits to the top surface that contacts the die's bottom? I have the die turned 1/4 turn past where it bottoms out against the shell holder.

I have not yet smoked a case to see where the contact is, nor done a detailed measurement at different stages up the case to compare a factory round that fits to my resized cases that don't. I will, but wondered if I might be missing something else.

Anyone have thoughts on this?

Thanks,
Chris

This rifle was offered on Gunsinternational awhile back before being auctioned elsewhere. Pics are still up on GI: https://www.gunsinternational.com/g...ble-rifle-8-x-57-jr.cfm?gun_id=101787360