|Sentry drone gun|
USA War Factory
This will upgrade Sentry Drones with a light autocannon, allowing them to attack enemy units and structures
The Sentry drone gun is a USA upgrade for the sentry drone, equipping it with a 20mm autocannon. This makes the Sentry Drone highly effective at tracking down and destroying stealthed enemy infantry, such as Black Lotus.
The Sentry Drone Gun upgrade is available from the USA War Factory.
The 20mm autocannon itself resembles the M85 .50 calibre AFV turret-mounted heavy machine gun due to the distinct heat shield and flash-suppressor. However the size and length of the gun do not correspond to the actual real-life M85, perhaps hinting that it is an auto-cannon with certain elements taken from the M85.
M85 machine gun at Wikipedia