I'm enjoying this build - the new barrel looks great! The drone looks fiddly - good job on it.
Is the M152 from a JLTV kit? Since the turret is supposed to be unmanned, you may want to add an extra large ammo box for whatever weapon you add there, or some automatic feed from inside the turret. OTOH, that would be tempting the crew to fire the 0.50 cal without stopping for a barrel change, so maybe an automatic feed isn't a good idea.