As Pete stated, rimfire cannot be trusted to ignite reliably. Go with a centerfire. If you're used to the Keltec .32acp, why not get a P3AT? A .380 is a fine BUG caliber. Or if you're itching for a revolver then pick up an inexpensive J-frame revolver in .38spl. I've got a Smith&Wesson 637 that weighs almost nothing, dissappears in a pocket, and packs enough wallop with Corbon DPX +P's.