I have this rifle, it'll knock the life right out of a squirrel but it's definitely not as quiet as a "whisper". It's got a good "crack" to it but nothing like a 22
Having said that, my cat is a murdering bastard, wanna borrow him ?
Having said that, my cat is a murdering bastard, wanna borrow him ?
Just about any single-shot break-action .177 or .22 pellet rifle will do the job.
I'd get one that has a factory-mounted sound suppressor. Spring-pistol airguns are pretty loud, and the neighbors might hear it even through closed windows, if they're sitting quietly at home. The air rifles with silencers (not removable, not functional for any real firearm) are quieter and thus better.
Try, for example, the Gamo "Whisper" rifle.
Shoots .177 pellets at around 1000 f.p.s. velocity. Should be good for killing squirrels at any distance you can hit them in their vitals. That's probably going to be around 50 feet. Maybe a bit longer if you experiment with a few different kinds of pellets.
Expect to pay about $120-$175 for the rifle.
P.S. Get one with a scope already mounted. It will make your life easier, trust me.