It would still need a person to aim it an fire it, so I think it would be best to put it somewhere raised but not so high that it would count as a tower.We could make a makeshift turret, using chains and a wheel and some wood, tho I think metal pipes would work better, we place it up high so its got some reach so a tower. Being a minigun it can mow down hundreds of raiders trying to assault the settlement. As long as no one uses a rocket or a mininuke on the tower.
Plus, it would shield it form someone trying to snipe it with a rocket or mini nuke.