Faced the end of the tube off.
Did some layout and marked off 0.375" intervals.
Squinting makes all my projects look better.
Picked a short and stout drill bit as I don't want to spot each hole. I believe this is a letter N. The diameter wasn't critical. What was critical was having enough rigidity in the bit that there was no wandering while drilling through both walls.
Staggered the holes.
Wanted a bit more aggressive look to it, so I milled off the end, cutting halfway through the outermost ring of holes.
It'll need tapered--as well as a couple threaded holes for set screws. Hmmmmmm...I suppose this will fit the R1 or Marksman Mod. 56 FTS. I'll find something.
Check back soon.