Years ago I found and bought 100 rds of yellow box Remington 30 Mauser pistol ammo, later Midway offered 7,62 or 7,63 empty brass too (along with 8mm Nambu). I found the 30 Mauser (7,62x25) in an old sporting goods store. Used 93gr lead bullets, 85 gr jackets and 100 gr half jackets in my Mauser 96 with light loads of Unique.
There was a popular wildcat 22/7,63x25 cartridge with barrels made for the Czech Model 52 pistol some twenty years ago
Mauser pistol target at 25 meters, should have used the stock
Attachment 127465