I have waffled back and forth over the years from target solids to hvhp's to hyper velocity rounds. After all the changes, I find myself coming back to regular old over the counter high velocity hollowpoints such as CCI Minimags. The trajectory is better than target loads, the accuracy is better than the hypers. Meat damage isn't too bad if you don't hit a spot on the backstrap or legs. Head or heart/lung shots are instant death, no crawling away or wondering if you missed completely. Regular old hvhp's are plentiful, inexpensive, and easy to find too. No mail ordering or haunting gun shows hoping to find some oddball favorite target load. If I were looking for some ammo to try for hunting squirrels and I hadn't already determined what was best for the particular rifle, I would go get a box each of CCI Minimags, Winchester Super X, Winchester Powerpoints, Federal Classics, and Remington Goldens. Shoot up a box for groups, and you'll know pretty quickly which one is the best for squirrel killing accuracy.