6-pounder gun or 6-pdr, usually denotes a 57-millimetre (2.2 in) gun firing a projectile weighing approximately 6 pounds (2.7 kg). Guns of this type include: * QF 6 pounder Hotchkiss, a 57 mm naval gun of the 1880s; a similar weapon was designed by Driggs-Schroeder for the US Navy * Driggs-Schroeder Marks II and III and Driggs-Seabury M1898 and M1900 57 mm guns on mobile mounts, used by the US Army circa 1890–1920 * QF 6 pounder 6 cwt Hotchkiss, a British 57 mm tank gun of 1917 * QF 6 pounder Nordenfelt, a 57 mm naval gun of the 1880s very similar to the Hotchkiss * Ordnance QF 6-pounder, a British 57 mm anti-tank and tank gun of World War II * QF 6 pounder 10 cwt gun, a British twin mount naval and coast defence gun 1937–1956.