Well, the barrel is 90% done. It's chambered, threaded, and installed. It locked up nice and tight and right on the money. Stuck the breech block in and no slop at all.
Cutting the threads turned out to be a piece of cake. I practiced on a piece of AL round stock. Saw what I had to do.
Because with a 10tpi change gear in the lathe I did the threads by hand. The carriage moves very fast and I didn't want to crash into the shoulder of the barrel.
So I moved the chuck by hand while keeping the half nuts engaged. Went to the end, returned the tool bit to a bit past zero, then reset. Took .001" off at each pass until I got to .035' deep.
Next step is cutting the slot in the bottom for the extractor/ejector and machining the flats on the side of the barrel. And of course trimming the barrel to 22", crowning it, and then tapering it. I'll do the dovetails later. It's easier to get the sights lined up when the barrel is in the receiver.
So, the real critical work is done.