I almost had some ammo from the Old Western Scrounger, but it was mislabeled and actually 297/250. It is easy to make from 22 Hornet brass. You simply shorten it to 0.6" or 0.8" for the short or long versions of the cartridge. The reloading info I have basically makes it a .22LR centerfire cartridge. The Handloaders Manual of Cartridge Conversions suggests 3 grains of Unique for 900'/sec in the short version with a 43 grain lead bullet. The say: Make from 22 Hornet, Run hornet case into 25 acp die until shoulder is established at.35" dim Neck ID may need reaming. Not necessary to FL size, 40 gr bullets. Fun little gun