Mass Pike Interchange

There's a handful of Gunners guarding the lower ground in a small outpost.To reach the actual gunner base high above the overpass, you must find the lift further north of the actual location, near the road.

The actual Gunners base in the overpass has several turrets and an assaultron guarding the base. The gunners are amply equipped so prepare for a firefight.

The Gunner Commander is found in the far end of the base and its possible that he won't join the firefight, allowing you to critically injure him or kill him with a sneak snipe or attack. There's a Power armor here that can be equipped by the Gunner Commander. Make sure to kill him before he gets in the armor. If he gets in, it will be difficult for you to forcibly eject him unless you can target his power armor's fusion core. If you killed him with the power armor on, you can still get the parts however you won't be able to acquire the frame.

There's also a Power Armor station nearby. The storage shack may contain Fusion Cores and other lootable containers. In the commander's shack, there's an issue of Grognak the Barbarian on the toilet seat and a steamer trunk