Manufactured from 1879 to 1887, the Model 320 revolving rifle is one of the rarest Smith & Wesson firearms produced with a total production of 977. These firearms were serial numbered from 1 to 977, and out of the 977 manufactured, 514 had the 18 inch barrel. Only 840 of these were sold in the U.S., and the remaining 137 were exported, with this example having British proofs. This Model 320 was manufactured using the frame, cylinder and basic action of the New Model No. 3 revolver with some minor differences in the hammer and trigger, with the barrel being made of two pieces. A slot is cut into the butt and a hole drilled in the back strap to accommodate the shoulder stock. The rifle features an 18 inch barrel with a two leaf folding rear sight (without a front sight) and a solid rib which is marked with the two line address/patent date marking. The matching serial number appears on the butt, cylinder, barrel and barrel latch. Blue finish with casehardened hammer and trigger guard. The left side of the barrel at the breech is stamped with two British proofs and the cylinder has British proofs stamped between the chambers. The left side plate is marked "WM MOORE & GREY/GUN MAKERS/43 OLD BOND STREET/LONDON W." The barrel is fitted with a checkered hard rubber red mottled forearm with the S&W monogram on the underside. The grips are matching with S&W monograms in a circle at the tops. The stock is smooth walnut with blue finished attaching iron and a checkered black hard rubber buttplate with S&W monogram.