Overall length 11.625; barrel length 6"; caliber .54. Markings: on lockplate, "US/DERINGER/ PHILADELIA" or merely "DERINGER/PHILADEL\" in the center; tail either plain or marked "U.S.N./(date)"; barrels sometimes marked with U.S. Navy inspection marks. Deringer was granted a contract with the U.S. Navy in 1845 for 1,200 of the new "boxlock" percussion pistols also made by Ames. All of these appear to have been delivered. From the extra parts, Deringer is thought to have assembled several hundred extra pistols, some of which he rifled. The latter bring a premium, even though quantities remain enigmatic.