Both pistols are double action. In a double action revolver, squeezing the trigger pulls back the hammer both to cock the gun as well as serving to release the hammer. In contrast, a single action revolver requires the hammer to be pulled back by hand before each shot.
A single shot percussion pistol, .36 caliber double action, fired by bar hammer. Pistol has an oval trigger guard hammer, trigger movable. Markings found on left side of hammer:: "ALLENS PATENT."
Metal. L 21 cm
Vicksburg National Military Park , VICK 1434
Made by Allen and Wheelock
Recovered from U.S.S. Cairo, this Allen and Wheelock Pepperbox Pistol is a six shot, 31 caliber, double action. This pistol was fired by bar hammer which has a small number "8" on the underside.
Metal. L 17.5, Dia (barrel) 3.18 cm
Vicksburg National Military Park , VICK 1419