This is another cartridge found among a box of stuff left by a friend.
No marks except for the three crimps in the case and two o the head.
Bullet dia. at the case mouth is 0.502.
Base dia. is 0.562.
Rim dia. is 0.642
Rim thickness is 0.070
Case length is 1.151
Cart. OAL is 1.603
Does this qualify as a “necked cartridge”? The closest I can come up with is 56-52 Spencer necked but the Case length and OAL are wrong.