Woodrow: years ago I had a High Standard derringer in 22 magnum. It was a well made little piece that you could slip into a pocket or a wallet type holster. All the other calibers aside, including the 44s and 45s, the 22 magnum worked incredibly well. I never used mine except to play with but a couple of fellas I knew had palm derringers, which were a Special Forces issue (at least to us) that took three shots in that caliber or, you could use the 22lr. One of the fellas used his to get his butt out of trouble one night. We didn't see the situation unfold but heard the shot. When we got there to look, one man was down - the one with the bolo machete in his hand and our man was standing over him. He had fired once with that derringer and the 22 magnum had created horrific damage penetrating and exiting the target. Mortality was immediate as a result of the damage.
As a result, I had waited for years to find another High Standard but they sort of disappeared from the market. I think they have come out again but I'm not sure. Failing a derringer in that caliber I was hoping to see a semi-auto come along and two did. One was the Grendel P-30, a farily large staggered magazine semi auto in that caliber with an interchangable barrel capability for longer shots and, the AMT 22 magnum version of the Hardballer. Unfortunately, Grendel has gone out of business and either the stainless steel or the overall design of the AMT isn't conducive to reliability, as I understand. I wish it wasn't so, as that caliber is pretty awesomely effective. Hope this helps. Mikey.