I had a Model 21 .22 LR and a Minx, (.22 short). As the gents stated the 21's are very ammo sensitive and the 21 I had jammed like crazy until I found the right ammo, (and a reliable magazine). I sold it off though and kept the Minx.

The little Minx will shoot about anything I load it up with. It's also very accurate for such a tiny pistol.

The 21 is a nice little pocket pistol and all the little Beretta pocket .22's seem to be pretty accurate. They're well built and will serve you well. I also love the tip up barrels.