Wow, four year old dig up.
At any rate, having contemplated a NAA mini-revolver for a "no other option BUG" I looked into .22 Mag. Hornady currently has a rather hot .22 Mag load out that is optimized for pistols and meant for self defense. Addresses many of the issues with shooting ammo meant for a 20" barrel out of a sub 4" barrel.
Hornady Manufacturing Company :: Ammunition :: Rimfire :: 22 WMR :: 22 WMR 45 gr FTX® Critical Defense®