Thinking about this now for 2 days, it occurs to me that a chamber cast is going to be larger than the cartridge for obvious reasons. So the case dimensions in Cartridges of the World is not really the way to asses a chamber cast.
Looking at the 8x57R/360 CHAMBER dimensions, (in the RWS reloading reference Wiederladen), it's starting to look like a closer match. What do you guys, who perhaps do this more often than me, think?
Chamber dimensions from reference:
R1. 12,45mm
P1. 11,03mm
P2. 9,73mm
H2. 8,80mm
L3. 57,30 (If my cast is 60mm, perhaps it's because chambers must allow for over-length cases?)
8x57R/360 Lauf = 8.07mm /.318" Interestingly this rifle barrel is stamped 8,2 and then what looks like "mm". In other words, .323", but the chamber cast does not agree.
Another dimension is L1 47,24mm on my cast which is the base to the top of the shoulder. It's only supposed to be 46,00mm. I guess cases are going to stretch a bit.
So, do we have a 8x57R/360? Stransky says, "A large number of shootable rifles chambered for the round still exist". Is this one of them?