My personal recomendation is to just use a .22 rifle (or long barreled pistol) with CB longs. Out of a rifle barrel they make less noise than my kid's BB-gun. I have used them for pest control up through large racoons and they work just fine. They put a 29 grain bullet out the end of the barrel at about 750 fps, and are accurate out to well over 50 yards.

One night I shot 3 racoons out of a tree 75 feet from a nursing home and could see the nurses inside going about their work. They never knew I was there. (Well maybe my squad car parked in the lot had something to do with it.) However they never heard anything.

Stay Safe