Oh shoot, I am no expert, I think they were offered primarily in 30 Mauser (hotter than 30 Luger) and there were some in 9mm that had Red 9 Grips (just finished one of those) to help keep it feed in 9mm Luger rounds. I did a Chinese 45 I think a while back! More from the experts. Note the first one is a Bolo and shorter barrel. Mauser Broomhandle C96s are a study in their own to learn all the variations.