People talk about rechambering weapons frequently and they usually do so by reaming out the chamber, removing material. I'd like to do the opposite.
I have a messed up Arisaka barrel that's been rechambered for 30-06 and has no collector value. My idea is to take the demilled barrel stub of a 7.62x39 AK rifle, reduce the outer diameter on a lathe, ream the chamber of the Arisaka barrel out, and press the AK chamber into the opened up Arisaka chamber. I understand that this will need to be very precise, as the chamber would have to be pressed in exactly, far enough away so that the bullet seats fully and doesn't get pushed into the rifling upon being chambered but not so far away that it jumps from the chamber to the rifling. I've been told that I would need to resleeve the barrel because "the material transition from AK stub to Arisaka barrel isn't going to line up perfectly and isn't going to be seamless. So your bullet will "catch' slightly there, and best case scenario, it's going to toss your accuracy all to poop". I'd rather not do this and use the original rifling instead.
Has this been done? Can this be done? I will be working with two skilled machinists who know what they're doing and I know how to check headspace. Labor cost is irrelevant.
Here's a mock-up of the placement of the chamber. The end of the colored pencil indicates where the rifling begins in the Arisaka. The barrel won't be going back into the Arisaka, it'll go into an AK.