This is a highly desirable example of a San Francisco gunsmith's custom modified Civil War Spencer Carbine to a heavy barrel hunting rifle. The top of the barrel is stamped with the gun-maker's name and address: "A. J. PLATE/SAN FRANCISCO CAL". The rifle has a heavy, full-octagon barrel with dovetailed, nickel silver, "Rocky Mountain" front sight and sporting style rear sight. The barrel has a brown finish. The barrel has an iron ramrod thimble that supports a wooden cleaning rod with pewter tip. The key-fastened walnut forearm has oval, nickel-silver escutcheons and a pewter tip. The rifle has the original military stock with sling bar and ring and lower sling swivel. The receiver, hammer, loading lever and buttplate have a casehardened finish. The top of the receiver is roll-stamped: "SPENCER REPEATING/RIFLE CO. BOSTON. MASS./PAT'D MARCH 6 1860". The serial number is located on the receiver tang. An adjustment screw is located on the lower tang behind the trigger. Several western gunsmiths converted surplus Spencer rifles and carbines to civilian sporting arms. An A.J. Plate heavy barrel Spencer Carbine conversion is illustrated on page 149 of "SPENCER REPEATING FIREARMS" by Roy M. Marcot.