I use a RWS 34.
A spring piston powerhouse in a break barrel rifle for up to 1000 fps. Automatic safety; rifled barrel. Combo includes a 4x32 compact scope and 2-piece C-mount. Barrel length: 19.5''. Overall length: 45''. Weight: 7.3 lbs.

No problems hitting squriels at the top of trees, the accuracy is about 1" at 20 yards. When the accuracy starts to fade I brush & clean the bore real good and it helps a lot.