A group of 94 percussion caps and lead shot from the 1845 British Northwest Passage Expedition led by Sir John Franklin. The percussion caps consist of flanged type-79, Smith patent type-4, and Small sporting type-11.

The percussion caps and lead shot were found by Lieutenant William R. Hobson's sledge team on 24 May 1859 at a place where a ship's boat was discovered on the coast of Erebus Bay, King William Island, as part of the search expedition led by Captain F. L. McClintock. McClintock visited the site on 30 May and records 'a linen bag of percussion caps of three sizes, a very large and old-fashioned kind, stamped 'Smith's patent'; a cap with a flange similar to the presents caps used by the Government, but smaller; and ordinary sporting caps of the smallest kind.'. [McClintock, Voyage of the Fox (1859), page 367].

The caps and shot were displayed at the Royal Naval Museum, Greenwich, in Case 2, No. 12. 'Percussion caps'. The items are shown in their original linen bag in 'Stereoscopic slides of the relics of Sir John Franklin's Expedition' photographed by Lieutenant Cheyne RN, at the United Services Museum, Whitehall, No. 7 (top centre) with its own label 'Percussion Caps'.