DD832 --
I refrained from posting, earlier, because with all the talk about lathes and drill presses and the advisability of just sending it off to be done, I feel like the backward country cousin who can't afford the good toys or the cost of having "people" to just do it for me.
I've cut the breeches off new and used barrels, and (like you) bought unbreeched tubes because the price was just too good to pass up (latest acquisition was, like yours, from Numrich -- a 30" x 1" .50 caliber). My drill press is a big tabletop model and I don't own a lathe. I clamp the barrel level (I do own a level) into a vise and simply drill a 37/64" hole the same depth as the length of the threads on the plug I've chosen for my latest project. I do enough building to have long-since found it worth my while to acquire both standard and bottom taps in 1/2", 9/16", 5/8", and 3/4". My plugs end up seated to the shoulder of the bore and indexed correctly to the flat of my choice. Sometimes there's a lot of trial and error, filing, and sweat involved, but the cash to cover the labor fee and shipping charges, to have Track or someone else do it, stays in my pocket.
Ye of little faith, indeed. I envy you your better tools, but above all admire your willingness to do the job yourself. :hatsoff: