Benjamin Trail NP Air Pistol .177
I used the break barrel Benjamin Trail NP Air Pistol .177 600 FPS for close range squirrel pest control and eliminated 6 last year. All were close range (under 10 yards) with mostly head shots. It killed them humanely.
I now have a stock Crosman 2240 .22cal rated at 460FPS, but being a .22cal it can go slower with the same similary stopping power to my .177 NP, so we'll see. I haven't bagged any yet. I only use pointed pellets because air pistols at low FPS, there won't be any expansion of hollow points. At low velocity, I want as much penetration as possible, so I go with the pointed pellets. If I had a high FPS air rifle, then I'd go with the hollow points.