The RML 64 pounder 64 cwt gun was a Rifled, Muzzle Loading (RML) naval, field or fortification artillery gun manufactured in England in the 19th century, which fired a projectile weighing approximately . "64 cwt" refers to the gun's weight rounded up to differentiate it from other "64-pounder" guns : 1 hundredweight (cwt) = 112 pounds.