Will Crosman C0-2 pwerlets work in a Benjamin air pistol?

Yes. All 12 oz powerletts are made the same. In fact Crosman owns both Benjamin and Sheridan air rifles. Also when you are finished shooting remove the powerlett from the pistol. Never leave one in the pistol, because it can warp the seal. It's not worth leaving it in the gun for a "70 cents" item to save money. The continuous pressure can damage your pistol.