Raimey,
No, I meant .516" head diameter. The largest diameter you measured was .525", and the chamber must be larger than the cartridge. You can't fit a .544" 450 head cartridge into a .525" hole. When I say "head diameter", don't get it confused with rim diameter( for MB base rim is .585", but .595" fits most rim recesses).
fuhrmann,
MB cartridges were available in calibers larger than 11.15, and longer than 60mm.
Mike

Last edited by Der Ami; 01/02/17 07:37 PM.