Ammunition is indeed very important to running .22 pistols. My brother has had an Erma Walther PPK copy for years, it has always been reliable. Same for his Ruger Mk1. My S&W M18 revolver likes certain ammo better than others. Some sticks in the cylinder, some fails to fire on the first strike. My Advantage Arms .22 conversion for the 1911 has been 100% reliable with the CCI Hi Vel ammo recommended. I had a Beretta micro tip up .22pistol that loved hi Vel ammo but faltered on regular stuff.