I have a .22 air rifle with a sniper sight. Bought it second hand and the guy sold the sight with the gun, even though the sight is waaayyyy to powerful a tool for that kinda gun.
We stripped in and boosted the compression. Boy, that think can pack a punch. It's in the attac now, don't really use it too much anymore.
Used to be able to hit a bullseye from 500 meters though.