Xd357 said:
It's got to be an custom add on. I wouldn't think Mr. Wesson would build that and try to sell them.
Sorry xd, but that's a factory barrel. That is one of the switch barrel Dan Wesson revolvers, and the model 15-2 was offered with barrel lengths of 2.5, 4, 6, 8, 10, and 15 inches, which is the one listed in that auction. They could be bought with one barrel and other barrels purchased separately, or they could be ordered in "Pistol Pacs" with 3 (or more) barrels that came in a fitted case with the barrel changing tool and clearance gauges.