This Ruger manufactured no bump adjustable rear sight sub-assembly is for the old model 3 screw Blackhawk single action revolver and is in very good condition with light wear. This sub-assembly consists of the body without bump, blade, windage spring and windage screw. (file photo)
Note: Ruger old model Blackhawk revolvers with the following calibers and serial numbers have been observed with this part:
30 Carbine: 50-01796 & 50-06496
357 Magnum: 90888