Looks like a fine day at the range!
As for European cartridges, their standard designations actually make more sense than most of ours. For instance, our commercial .224 centerfires have names like .22 Hornet, .218 Bee, .221 Fireball, .222 Remington, .223 Remington, .222 Remington Magnum (which is far less powerful than several other .224 centerfires), .22-250 Remington (even though it wasn't invented by Remington), .220 Swift and .223 WSSM. These days ALL of them use the same diameter bullets, but their names sure don't show it, and the rest of the name usually doesn't tell us much either, aside from "Swift" (it's fast, though not as fast as the .223 WSSM), and .22-250, which means it's the .250 Savage necked down. But you have to know that to understand it.
European cartridges are fairly simple. Take the 9.3x74R as an example: 9.3 is the diameter of the bullet in millimeters, 74 the length of the case in millimeters, and an R at the end mean the case is rimmed, as opposed to "rimless" like the .30-06.
There are some exceptions. The 8x57 comes in both J and JS versions, the J meaning a .318" diameter bullet and the JS meaning a .323" bullet. But that's just a historical note, like the name of the .250-3000 Savage denoting the velocity of both the bore diameter and the muzzle velocity of the original 87-grain factory load.
