Se the black mark on the drill bit? That's my stopping point, the rr is the full length of the barrel. So the RR groove stops where the comfy zone is for balance. Then a 10-12" blind hole begins
I try to measure and make sure about 5 times that my drill bit will not wander....so that the clamped part making a pilot hole if you will....
A perfect hole stays centered, and 1/8"-3/16" below the barrel breach......my attempt on this one was 1/4".....but centered.
Not a problem, but it means my forearm will be 1/16" fatter than I wanted....won't be noticeable.....
Builders get to fretting more than a teenage girl about hairdos ....
Drill 1/4" and then remove chips....repeat.....soap is the lube....but the bit still gets pretty hot! And I used to use Jacobs hand drill for this job.....
Cutting the groove properly is the hard part.......if it all goes bad, and your bit comes out of the stock back by the breach......tomtom get another scratchin post!
Marc n tomtom