Tank gunnery training aid.

[sapper740]

Originally Posted by Tommy K

Surely the Thompson wasn't for the main gun as the range would have been pityful. Maybe it was a substitute for the turret mounted machine gun.

No, it was definitely a training aid for new gunners to get used to hearing a bang when practicing their firing routine, although, in the case of the Thompson, it wasn't meant to parallel the main gun's ballistics. This set up wouldn't have worked in combat for several reasons: the 20 round mag would need frequent replacement by a crew member exposing themselves to enemy fire and the wire to the solenoid would have been susceptible to damage. Derek.