Sir Joseph Whitworth, 1st Baronet (1802-1887) designed his famous "sharpshooter" rifle with distinctive hexagonal rifling in the 1850s, and they quickly earned a reputation for long range accuracy in the hands of both British target shooters and Confederate sharpshooters during the American Civil War. This fine example featured a dovetailed front sight, long range rear sight with folding leaves for 100 and 200 yards and a folding ladder graduated from 300 to 900 yards and gold sight lines, "WHITWORTH PATENT" marked ahead of the rear sight, and "258" and Birmingham black powder proofs and "52" bore markings on the underside. The breech plug is engraved with a reposed stag on top and has "258" on the hook. "258" is also marked on the trigger guard tang and on the inside of the patchbox. The lock is marked "WHITWORTH PATENT" and has a half-cock safety ahead of the hammer and fine scroll and border engraving that on the hammer is inhabited by a bird and a snake . Coordinating engraving is found on the furniture, and the patchbox features a scene of a stag pursued by a dog. The stock has a dark horn forend cap, checkering on the forend and wrist, a sling stud on the bottom of the butt, and a blank silver oval escutcheon. The rifle comes in an associated fitted takedown case with a Whitworth Rifle Company trade label, wad tin, black leather bound Hawksley powder flask, T-shaped combination tool, wood compartment, octagonal steel oiler, additional tools and cleaning attachments, and a brown leather sling. The accompanying "FIREARMS INVENTORY/THE PHILIP B. SHARPE RESEARCH LABORATORIES" document lists various details of the rifle. Also includes handwritten "Instructions for loading the Whitworth Sporting rifle" dated January 13th, 1860, and addressed "To His Grace the Duke of Somerset/Admiralty." Edward A. St. Maur (1804-1885), 12th Duke of Somerset, was First Lord of the Admiralty and was previously the First Commissioner of Woods and Forests and First Commissioner of Works. As First Lord of the Admiralty, he was involved in the consideration of Whitworth's naval guns for adoption by the Royal Navy. The rifle is noted by serial number on the representative print of a test target which states a load of 55 grains or 2 drams of "Good coarse grain" powder and a 530 grain bullet were used. Provenance: The Collection of the Duke of Somerset; The Philip B. Sharpe Collection; The Norman R. Blank Collection