Have you seen the extended version of ‘Aliens’? In the longer cut, the surviving Marines who are marooned on LV-426 deploy remote sentry weapons outside their makeshift fortress to hold off the advancing aliens while Bishop the android remote-pilots the backup dropship from the orbiting Sulaco to rescue them.
The robotic guns work beautifully — for a while — until the approaching xenomorph horde proves to be too many for the weapons and exhausts their ammunition supply.