The gun was originally designed to replace the Egyptian police's obsolete Martini–Henry rifles, which they usually loaded with brass shot-shells. The Mark I/14 ("14" for the gun's gauge), first produced in 1918, had a full wooden stock and a large metal nosecap over the muzzle. The Mark II/14 lacked the nosecap and had a full hunting-style stock. It was discovered that criminals in Egypt were jury-rigging shotguns they had captured or stolen by wrapping common civilian 16-gauge shells with thick paper to allow them to fit the bore. Greener responded in 1932 by coming up with a redesigned gun and new shell design to prevent this. The Mark III/14 Shotgun had a three-pronged firing pin and its cartridge had a unique recessed primer well (much like that of the Lebel rifle) to prevent the firing of standard shells. The cartridge also had a bottle-necked tapered wall and corresponding shotgun breech that would prevent the insertion of other shells.