I don't know what you are mounting it on but if you have to get a drill and tap, I suggest going with a Marlin 336 base for the FF II....it is very clean looking and mounts with only 2 holes as opposed to 4 with a Pic rail.....And Gobbler74 guards are very nice as well. I have both....1 with a 336 base and 1 with a pic rail and I very much prefer the 336 base mount over the pic rail.