Original Item: The Lewis Light Machine Gun (LMG) uses an unusual drum magazine. The entire under side of the magazine is open, and the outer shell of the magazine rotates to feed cartridges into the gun. The central core of the magazine does not rotate but is latched to the receiver. The outer rim of the magazine supports the base of the cartridge, while the cartridge neck is held in position by steel pins. If the outer rim of the magazine becomes distorted or if any of the pins is bent, the magazine will not feed properly.
To address this requirement, a magazine gauge device and a magazine repair tool were issued at battalion level. The gauge indicates whether the outer rim is distorted and whether any of the pins are bent.
The tool is two-ended, one end being designed to reshape the magazine rim and the other end to straighten bent pins. It is marked:
GUN LEWIS .303 H.W & S. 1930
TOOL ADJUSTING MAGAZINE
NOTE: The tool is not described in any of the current literature available on the Lewis gun. This is the first place where the tool is described outside original ordnance manuals.