with so much high quality 22 WMR ammo out there...Hornady 45 grain FTX is my personal choice, also Federal 50 grain, and tons of others (18 in total I think), you CANT go wrong with this gun.
I recommend using a TUFF CLOTH to lubricate it after cleaning. Tuff Cloth is a dry lubricant, it will allow longer use before cleaning, and prevent jams.