"Mentolio"Yeah, pretty much what 30cal said. Also to be considered: .22 trajectory (arc of travel from muzzle to target) is a lot more extreme than in the .177 caliber (due to lower velocity and heavier pellet weight). It's an unfortunate side effect of "economy" that Crosman/Benjamin NP guns (and probably all other manufacturers as well) share the same power plant between calibers. A .22 Trail NP has all the same parts (piston, seal, Nitro Piston, etc) as the .177 Trail NP, with the exception of the barrel. It would be great if the larger calibers moved more air to compensate for the larger slugs, but they don't. My Trail is currently a .22, but I'm considering going back to .177. I find it to be much more accurate and not significantly less powerful.
sorry, almost forgot: while my accuracy ain't stellar in .22, my trail seems to really like CP 14.3s from the brown box. I am also experimenting with some H&N hollow points that are just under 13 grains. They look promising for short range (25 yards and less) so far.