The Berreta is very, very picky about its ammo. My dad found that Thunderbolts work best in his. Anyway back to the question, Kel-Tecs are pretty cheap and a .22 would be cool, but seeing as how they have two outstanding pocket guns(the P-32 and the P-3AT) I see no real market for one. Anything smaller than those just mentioned would be too hard to shoot acurately and with a .22(or any gun) you need to make your hits count. If you want to look at some .22 pocket pistols go to www.mouseguns.com.