I am so blown away, as the younger generation says, by the video. I hardly know where to begin. To start, let me say how this would be done industrially (or in metal by someone with a decent long-bed metalworking lathe). We have a treadle lathe here. Continous motion. So what you would do is put a
chuck in the tailstock. I know he has a tailstock, it appears in the latter portion of the video. Whether it accepts a chuck is unknown. You would
center-drill.. A center drill is a very stiff drill that will drill say 6mm deep, no more. This will give you a starting hole. Then you would switch the center drill for a twist drill and drill out to depth. I'd use say 3mm. If I had a long enough 3 mm drill. Then 6mm. If I heard Mr Driller right he is going "19 mils" I suppose that is 19 mm. OK, large hole. I think the length of the piece is about 10cm long and how it stays put without wobbling at the end is a miracle, or at last unexplained. I would use a steady rest

. If I had a long enough drill I would try something bigger than 6mm. After that, it's
boring. No, not tedious. You set up a
boring bar between centers and traverse the work along the bed. Concentricity assured. The cutting bit is crosswise to the boring bar. You adjust it to bore out the diameter you want. In metal it takes several passes; might be done in fewer passes in wood. There are variations on this program but that's the way you bore long holes true. It is called
line boring in the trade.
Not this guy. He is doing "experimental archeology" as he puts it. How did they do it back in the day? Really valid question. He starts the hole with a plain old ladyfinger gouge. I can't believe he can do that but there it is on the video. Then he uses a handmade boring tool to ream out the work. This is very impressive. I would have to ruin quite a few practice pieces before I developed that skill. Note how he withdraws the boring tool to clear chips. As to using a parting tool to turn the diameter, and I am again blown away. Would use a skew myself. Learn something new every day. When I finish this post I will go right back and watch the whole series from start to finish. And note that he says not to try this on a pole lathe!
It is well to remember what he is trying to do. He is making a one-charge gunpowder holder. It must exactly match the approved charge for your musket. So many grams (or grains in those days) of gunpowder. Drill too deep or too wide and your piece blows up in your face. Too shallow or narrow, your musket is underpowered. So this is high-tech, 15th or 16th century variety. I really applaud this video, and the turner himself. Bravissimo. Thanks for posting it.