I’ve got a darn good Remington barrel that has no taper, 24 inches long .625 diameter and the bore is in nice shape. We have a CZ 457 in an At-One stock and it’s a pig. I’m thinking that I can scuff up that barrel and glue it into a piece of .188 wall 1” 6061 aluminum tubing with Loctite 262 and take a lot of weight off the rifle.
My motivation for doing this is that my son is really compact and although the stock shortens up to where he can shoot it, it is pretty heavy.
Unless I’m missing something it appears that there really isn’t anything any more complicated than making certain to get the dimensions right. I’ve been looking at the barrel tenon and it’s straight with a small relief groove at the shoulder. The extractor cuts are on the CL of the bore like most bolt action rimfires and it has a shelf that sits on the bolt guide preventing it from rotating. The barrel grub screws tighten up against shoulders that are created by a couple 90 degree cuts.