Also known as the Model 1843 or Navy Box Lock Model 1843 manufactured by N.P. Ames of Springfield Massachusetts and Henry Derringer of Philadelphia circa 1842 to 1847. Ames manufactured about 2,000 of these pistols. The pistol had a bright barrel and swivel type steel ramrod with a button shaped head, casehardened lock plate and hammer and silver plated brass trigger guard, barrel band and flat, round butt cap and the later flat lock plate. The breech end of the barrel is marked "USN / 1845 / RP / P" and the lock is marked "USN / 1845" vertically at the rear and "N.P. AMES / SPRINGFIELD / MASS." below the hammer. The stock is smooth one piece walnut with no visible cartouches or inspection markings. The Model 1842 has the distinction of being the first U.S. martial percussion pistol produced under contract for the government. Ames delivered 300 of these pistols to the government before the contract was signed.

Very fine. The barrel retains 60% of the original brown finish with some thinning and areas of gray patina and some minor pitting. The lock retains 75% of the original case colors with a smooth gray on the balance and on the hammer. The trigger guard and barrel band retain 90% of the original silver plating with an aged patina on the balance and the buttplate shows strong silver with an aged patina and numerous small dings. The stock is very fine with a small crack ahead of the lock, some scattered dark areas, a few chips on the edge of the butt and a number of minor dings on the butt. The markings are mostly crisp and clear. The action is excellent.