I'm by no means an airgun expert, mine shoots an 8 grn pellet at around 825 fps which works great for Rats. Gamo (Cabelea's) makes a .117 or .22 with a scope that is around 1300 fps ( a little faster than the speed of sound). which would likely get the job done out to 30 yards or so, The downside is a pellet will go through my wooden fence and what happens after that is anybody's guess, in other words, they are nearly as dangerous as a regular .22 rifle.
I live trap raiding Raccoons and shoot them in the back of the head, in the trap, with my pellet pistol,
Check on the season for Raccoons, you don't want to be caught hunting any seasonal game out of season and without a hunting license. It's all fun and games until your nosey neighbor calls the Cops and you have to start producing the proper paperwork. In most places trapping problem animals is legal, but the fine print changes from local to local. Shooting varmints is all about location and in many places a pellet rifle is considered a firearm. Nobody wants a firearms violation on their record.