The Winchester lever actions don't use the same screw adjustable bushing around the bbl shank to take up wear in the TD joint like the Winchester 97.12.and 42 do.
The rifles all use 3 set screws threaded into the front face (inside the wood) of the bbl extension.
If the TD joint is loose and they often are even with the magazine tube tightened up as much as possible, the set screws are used to rather crudely take up the looseness in the joint.
Those screws are accessed by removing the forend wood.
Then they are carefully and slowly tightened which pushes/dimples out the back side of the bbl extension that mates with the front of the frame. That makes for a tighter interference fit when assembled,,and that's your adjustment for a loose TD.
It doesn't afford too much range nor much bearing surface. So it wears quickly when it is adjusted and runs out of adjustment soon after you start using it if TD is a favorite past time.
Many people just kept tightening and over tightening the magazine tube thinking that was the key to keeping things tight. But the tube mearly threads into the frame thru the bbl extension. It doesn't draw the assemblys together.
When you start using the, it will leave a noticable gap betw the bbl extension and the frame of the rifle as you are pushing the two components apart
To avoid using the 3 set screws, the bbl threads can be swaged forward to tighten the fit. A simple narrow flat faced punch working the entire thread from start to finish toward the muzzle increases the draw and tightens the assembly as it's cranked together it's 90*'s.
This will make for a tight assembly with the ability to still TD the rifle if needed. BUT, continued TD will loosen the joint once again. Better to assemble and leave it. Admire it as a TD and use it as a non-TD unless you want to get into other more costly methods to repair that don't make a mess of things.
I don't know if the repops use the orig Winchester setscrew type adj system or not. Maybe they do use a style like the M12 ect. That'd be great.
FWIW, that M12/42/97 adj is for TD looseness. Headspace is governed by the 'chamber ring' in the frame. A removeable spacer just inside the frame in front of the bolt held with 2 small screws. Approx 1/4 thick it's considered part of the chamber length , the bbl breech adj bushing sits against that to make a tight TD. When it gets loose, the bushing is backed out a notch or 2 to make contact again.
The bushing & the chamber ring are doing the same job as those set screws against the frame in the lever action TD system,,just a little more elegantly!
Spare time is not in my immediate future either.
