Johnston light machine gun
A rare light machine gun resembling the Lewis Gun.
The Johnston Model D1918 is a light machine gun, an uncommon and obscure firearm about which little is known. Its most notable feature is its visual similarity to the Lewis Gun, sharing a gas-operated action and a barrel encased in a cooling shroud. It fired the .30-06 cartridge from double drum magazines. The gas system worked through a piston housed in a cylinder located beneath and attached to the barrel. Unlike the Lewis Gun, the Johnston did not use a clock spring. Its cocking mechanism was distinctive: the entire pistol grip slid forward to engage the action, then pulled back to cock it. This movement was unlocked by a trigger-like mechanism set in a cutout behind the firing trigger within the grip. The cooling shroud could be removed by hand, without tools, by unscrewing the front retaining ring from the barrel. Inside, the aluminum cooling fins were split into two pieces; once the shroud was off, they came loose from the barrel. A cold barrel could be unscrewed for field replacement. An integral bipod was attached to the shroud. A variant existed without the heat shield jacket, featuring a bare, unfinned barrel. To maintain normal balance, a muzzle counterweight was added. This version also included a wooden handgrip ahead of the receiver, since the bare barrel would become too hot to hold, unlike the shrouded design.
Quick Facts
- Is Ranged
- yes
- Origin
- United States
- Cartridge
- .30-06 Springfield
- Feed
- double drum magazine
- Action
- gas-operated
Facts from the source article.
Lore & Background
The Johnston Model D1918 is a light machine gun chambered for the .30-06 round and fed from double drum magazines. Its action is gas-operated, with the piston working in a cylinder beneath and integral with the barrel. Unlike the Lewis Gun, the Johnston does not use the Lewis's prominent clock spring. Cocking of the piece is unusual: the entire pistol grip slides forwards to engage the action, then returns backwards to cock it. This is first unlocked by a trigger-like mechanism in a cutout through the grip, behind the firing trigger.
The cooling shroud can be removed without tools by unscrewing the front retaining ring from the barrel by hand. The aluminium cooling fins inside are in two pieces and, once the shroud is removed, come loose from the barrel. A cold barrel can be unscrewed for field exchange. An integral bipod is attached to the shroud.
A variant was produced without the heat shield jacket and with a bare, unfinned barrel. A muzzle counterweight maintains the normal balance position. A further wooden handgrip is provided ahead of the receiver, as the bare barrel would be too hot to hold, unlike the cooling shroud.
Reader's Guide
The Johnston Model D1918 is notable primarily for its resemblance to the Lewis Gun, though it differs in several mechanical details. Its unusual cocking mechanism, where the entire pistol grip slides forward and back, distinguishes it from other light machine guns of its era. The weapon's cooling shroud, removable without tools, and the two-piece aluminium cooling fins that come loose when the shroud is removed, indicate a design intended for field maintenance. The variant without the thermal jacket, featuring a bare barrel and a muzzle counterweight, suggests an attempt to reduce weight or simplify production, though the addition of a wooden handgrip ahead of the receiver acknowledges the heat issue. The Johnston remains a rare and little-known weapon, with scant information available on it, and its legacy is largely defined by its obscurity and its visual and mechanical kinship with the more famous Lewis Gun.
Did You Know?
- The Johnston Model D1918 is best known for its resemblance to the Lewis Gun.
- Cocking is performed by sliding the entire pistol grip forwards and then backwards.
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