It is explosive on small game. I haven't tried it on varmints, but I bet it would be awesome. It is pretty simple to use and once you get the feel of it, there is a variety of different shapes you can make with the same tool. You can do it just lightly and make ammo that performs better than the CCI Velocitor...or you can use it to 'clean-up' Velocitors or other high-priced ammo. If you look at those spendy bullets under a magnifier, you will see a lot of blemishes and deformity. Just a little tap with Paco's tool will straighten them out. You can also make a full wad-cutter hollow-point from el-cheapo ammo, but in most firearms these will not cycle semi-auto because of the sharp edge of the bullet. I have used them on Stingers and they are probably the most explosive I have seen, they will shred a pop can full of water, literally rip it into peices. I have used it on 22 Mag..although it is not realy made for 22 Mag, and could be a little dangerous..but it is pretty incredible what a 22 Mag will do with a 'Nasty-Nose'.