That's the problem with attempting to assign some percentage of added or reduced value to a gun that has been sleeved. So much of it depends upon the quality of the workmanship. Someone posted a photo of a sleeved gun here recently that had a very visible joint that was still very evident despite the ugly chicken scratch engraving that was applied over the joint in an attempt to conceal it. At the other end of extremes is this .405 Winchester double rifle built on a Simson shotgun action by the late Bob Hynden:
https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=439017#Post439017I also agree with Miller about having a concern over the HAZ (Heat Affected Zone) in an area where pressures are still very high in sleeved guns where TIG welding is used in place of solder or brazing. No question that guns done that way have the most undetectable sleeving joint, but there is no way to post anneal without also melting the brazing of the barrel lugs and stubs. I know barrel steel isn't high enough carbon to become brittle from air quenching during cooling, but I'd like to see some actual pressure testing of the two methods to know for sure.
