I have the miniturret on and the battery requirement to false (no need for battery to operate), have a pistol in the turret with ammo, authorized and everything... but it just points straight up.  Will it engage when near another player?  Doesn't seem to do anything with bots/scientists.

There's an invisible switch on the front of it.

Yeah, it took me a moment to notice the switch as well haha

Still... doesn't attack bots.  Does seem to target the roadside Scientists, but no bots.  That's unfortunate.