Each pistol has its own unique characteristics that will require you to experiment to see which pellet works best for your particular pistol. I would suggest you buy a sample pack from one of the pellet manufacturers and find out which one works for you. The settings of hammer spring and other "tuning" done to the pistol will also affect accuracy. jsb-testing-set-exact-.22
Above is one for JSB but other well know pellet producers have similar. Stay away from the new Crosman pellets, they are now made in Spain and are nothing but garbage. Here is a similar thread with some suggestions for you to consider: