I have been cutting them on a drill press for years,get a cheap holesaw grind the teeth off and sharpen it,back the drill bit up so it doesn't cut a hole in the fabric.Take a piece of thin plywood and drill a hole in it the same size as the hole saw clamp the fabric between the plywood and another board on the table, line up the hole saw with the hole in the plywood and drill away.Its takes a lot longer to descibe than to knock out a thousand patches.Then I discovered the wife's cutting board and rotary cutter so I cut square patches a lot easier.I can't see any difference in shooting results.You might want to buy an extra blade or two for the cutter so you don't upset the wife when she finds she has a dull cutter.