Steady rest, live center, or other way ??...

[56type]

Another option is a "cat's head", or "steady rest spider." It can eliminate the rubbing on the barrel and can handle stuff like hex and octagon as well as round.
https://www.youtube.com/results?search_query=steady+rest+spider

I'll go thru those and see what all it takes to make one. Thanks Again Bob !!

 

[56type]

Make center-drilled plugs for chamber and muzzle end, them spin the barrel between centers, muzzle at headstock, chamber end at tailstock.

This is commonly done in turning- think "crownsaver" for the muzzle end. Alternately, you could just use a 7.62 x 39 case as a center in the chamber. As you said, tolerances on AK variants are pretty loose.

Sorry but I'm having a bit of trouble picturing it...Not sure how the plugs would work exactly. If I put the 7.62 x 39 case in the chamber (minus the fired primer for the center), it would seem the barrel would be rotating on the thin walls of the case with the live center in the primer pocket, correct ?? Could you better describe the muzzle end plug & how it would work without spinning in the bore ?? Thanks.

 

[Silverbullet]

It would be riding on the brass , what better to not Mar the barrel or chamber . The live tail center will spin freely and if it's aligned with the head stock there shouldn't be a problem it it's not lined up on the bore where the center is it never will be .

 

[dulltool17]

Yep, Silverbullet described it pretty well. Brass cases are thicker as you get to the rim, so it really isn't " thin" brass.
The plug at the muzzle end needs to be close to a light press fit. Once you are done with the operation, you pull the case and use your cleaning rod to tap out the muzzle plug. This is an operation that requires a bit of patience.