Sn: 6229. Bore is very good. Action works perfectly. This is the No.2 model. Barrel length is 2 1/2″. Grips are excellent with perfect checkering and 98% varnish. Has approximately 80% silver plate, some of which is tarnished. We did not polish the tarnished areas, but the new owner can do so and the derringer will really sparkle. A very fine example.