You say you can buy a 70-ish year old broach-cut machine gun barrel for $75, but you know about new GM button-rifled barrels for $50-ish. Hmmmm. IME, most military broach-cut barrels were not necessarily stellar performers in the accuracy department, and the 1919 barrel is more expensive than the GM blank.
I asked a question...
FYI, I know two people that have repurposed TGI barrels from the UK-59 MG that shoot bugholes. I'm well aware that MG barrels were not produced for stellar accuracy.
As usual, most here can't simply reply to the question ASKED.
Which was " Anyone cut one of these back and thread/chambered it?"
Note that I did not ask, "Do you suppose..." or "Do you think...".
I asked for direct knowledge.
You say you are the machinist, and can do all of the work yourself, and are asking how to sleeve the 1.12" breech end of the barrel, but you can get a GM barrel blank of the proper 1.20" diameter to begin with. According to your drawing, you don't need to sleeve the breech end of the barrel, just thread it and screw it into the action. You will have a smallish barrel shank, but there will be enough of a shoulder to seat on the action face.
Ignoring the insult because I'm in a good mood today...
The tenon could be sleeved by the method stated above- Cutting Class B threads on a sleeve, threading it on, then cutting the new receiver threads- IF IF IF the numbers work. Damn if I would cut a sleeve with ten thou between the minor diameter of the new threads and the major of the old.
The tenon could ALSO be sleeved by turning off the threads- and the splines for the barrel extension.
THAT was the reason for the question. I know what a sleeve, is....
Listen,
I'm asking if anyone has direct experience. Period.
I know all about blanks from Green Mountain, Shilen, Krieger, Brux, blah , blah, blah.
I was asked by a customer if I KNEW anything about their accuracy and if it was a worthwhile project.
If you DO NOT have direct knowledge of the results of a M1919 re-barrel on a bolt gun, please do NOT reply to my thread.