I've used this hole cutter to cut a 4 inch hole on one of my bass drums and a 6 inch hole. Cuts a perfect hole each time. Just make sure you apply lots of pressure and do it on a hard surface. Takes a couple tries going around with the tool but it will cut through the bass head. Good luck and buy this with confidence!
This thing works like a charm for cutting a port hole in your reso head. You can cut anywhere from a 2" hole up to a 10" hole. The blade is good and sharp and cuts like butter. If you own a cutting mat I'd suggest using it, cardboard as a cutting surface doesn't work so good. Have you ever tried to purchase an 8" dampening ring? You can't because none of the big brands manufacture one. I used an old clear single ply head, cut perfect 8" dampening ring and the best part is you can cut it any width you want for different levels of dampening. I highly recomend this cutter if youre trying to cut a hole in any head for any reason.