This 10 inch wide cartridge box has hand forged frame buckles and a wooden frame inside in which to dump loose cartridges.  I feel this is a transition box, rare to find from 1790-1812 . The buckles help date this and just look at the size.  Looks like an outline of an ordnance bomb on the flap in center.  Wonderful condition 18th century piece. 
Condition: missing plate on flap