Re: Need Help with my McMil Adj A3-5
You should have enough room. Look at the McM website at their rifles. The TAC 338 shows approximate location. I use a 1/2 Forstner bit and 9/16x18 bottoming tap with my drill press. I'll use a Sharpie to mark my hole and hit it lightly with a center punch or nail or whatever. I set the stock up on my drill press with levels, shims and clamp to get it just right. Drill my holes about 1/8th inch deeper then needed so I know I went deep enough on the first shot. I will then put my tap in the chuck and turn it by hand while pulling down lightly on the drill press arm thingy while letting the tap cut slowly. Do not let go of the arm while the tap is in. Slowly reverse it as you let up on the arm. It sometimes helps to have an extra hand. In my case it's my wife who thinks I'm nuts. It also might be easier for you to tap it by hand just take your time. If you fuck up you can always fill the hole and start over.
