the 32-20 cartidge was designed for the model 1873 Winchester lever action rifle. Colt subsequently produced a single action revolver which chambered this cartridge, and was fairly popular--probably this is the gun alluded, which would by then have been obsolete and derisible. The 32 is the caliber (.32" dia.) and the 20 is the number of grains of black powder in the cartridge. Ray Ott