This is an 1850s-1870s Ethan Aller, or maybe an Allen & Thurber Derringer "STYLE" single shot pistol.The trigger return spring finally collapsed, but we will make it work again, and soon. This tiny gun is chambered for .22 Rimfire, which was a black powder .22" rimfire cartridge the same size as today's .22 Short. .22 Short CB is about the same power as .22 Rimfire black powder. There is no such thing as .22 Rimfire smokeless, so always use CB in a black powder .22. .22 Short also works in some lever, & pump action rifles, and back when men were men, before the liberal media and academia turned them all into a bunch whiny annoying liberal hipster eunuchs, there were "gallery guns" where you could shoot at targets with a .22 Short rifle at "shooting galleries" in 10s of 1000s of amusement parks, county fairs, and other traveling shows. Disneyland had 3 shooting galleries, with live ammo! These rounds are great for back yard shooting gallery type target practice, antique .22 Rimfire guns, and even hunting rats & even feral cats. Feral cats have driven some of the most beautiful song birds in the world to extinction. Now that a tiger has tested positive for Covid19 outdoor cats are more fair game than ever. All cats from tigers, lions, jaguars, leopards, mountain lion, bobcat, lynx, ocelot, and house cats can all be interbred, and beside the same number of chromosomes they also share 98% of their DNA together. I prefer to live trap feral cats & dunk the cage in water to drown the cat. It's fast, painless, humane and quiet. Rats: We wound up with an infestation of something people call "roof rats". Rats predominantly eat pet food that people leave outside to feed stray cats, and pet dogs. The rats also carry diseases too. Rats eating citrus is a myth. Rats and mice cannot survive eating fruit that is 88% water. I have gutted two dozen roof rats. Everyone of the rats killed had a gut filled with dog food, cat food, human food, and or grain. The holes in citrus are put there by birds like woodpeckers & flickers, who drill a hole in a grapefruit, and come back daily to eat the insects the rotting fruit attracts. Cats have decimated many native songbird species into extinction. They have also decimated reptile amphibian, and even small mammals to extinction too. THEY ARE PESTS! PEST CONTROL TIME! So shooting gallery target shooting, antique .22 Rimfire, or backyard pest control, with the proper guns, this CB ammo works for many things, but it is especially great for antique black powder guns, and gallery type target shooting. I prefer the CCI low noise truncated cone .22LR hollow point for pest control. CB is a conical tip bullet. I do use .22 Short in revolvers, and in rifles that will shoot .22 Short. I also have some gallery target autoloaders that are designed for .22 Short CB. The Beretta Minx is a .22 Short autoloader, but .22 Short CB will NOT cycle that gun, or most other autoloaders. The ammo is top quality, and it's a real kick to shoot 140-175 year old gambler, & brothel guns of the wild west, or the old Mississippi riverboats & ol' New Oleans French Quarter gambling houses & whore houses. This cleans up a lot better than black powder too! And it's non-corrosive! I got lucky and scored this and Stingers at my Walmart for a really super good price. That's super rare. I prefer to give my money to Target Sports, or other online sellers over Walmart, but ammo in the hand now beats ammo shipped ??? Target Sports has good selection and they will be back up to speed after this Covid19 thing is all over with. Had I not needed a prescription filled, bleach & laundry soap, I'd have never gone out let alone gone into a Walmart, but while I was there, why not? .22 Short at a Walmart is very unusual. I think they're just making their shelves look less empty.