According to the "unboxing" video the AFU did of a captured turtle tank a few weeks ago, the main gun isn't even functional. I'd be surprised if the machine gun works.
Whats the point of sending a tank into battle without its main gun non-functional? Intimidation? Very small APC? Its got a functioning engine and can drive faster than walking speed?
It's basically just a ultra cheapo disposable APC. Tanks that were too broken to be refurbished after being stored in the open for half a century. The driver can barely see, there are no defensive weapons and the mobiks just ride along on top inside the "shed". From what I've seen, they are not really expected to return after dropping off the troops.
I initially thought that the main gun on that may have just broken along the way, but the fact that the reloading door was welded shut certainly corrects my error. I wonder if this was some kind of training tank to teach driving, so it would never had need of functional turret or ammo loading system.