Hmm....Step One: check local regs. In most areas, an air rifle (BB gun, etc.) is classified as a firearm. Discharging one within most neighborhoods is a big no-no. Also, anything potent enough to dispatch squirrels will be loud enough to disturb the neighbors.
As you may see in an earlier reply of mine, I definitely took your good advice and checked local laws/regs.....and you were dead-on right. My city bans such things UNLESS you go get a 90-day permit (seems silly to me; either allow it or don’t, but.....).
Thank you; appreciate it.