Artillery Piece (Fallout 4)

The artillery piece is a constructible settlement item featured in Fallout 4 and Fallout 76, which is available after the completion of the Old Guns quest.

Characteristics
The artillery piece is a mortar that consecutively fires up to five highly-damaging shells with a high level of precision and accuracy. Its ammunition is unlimited, and its maximum range is approximately a five sector radius, as viewed on the Pip-Boy's world map. It becomes active only after a settler is assigned to operate it.

Artillery strikes are called down by throwing an artillery smoke grenade into a target area that is within range of active artillery. Fire mission progress may be monitored on Radio Freedom.

If multiple settlements with active artillery are within range of a target, all of them may engage, significantly increasing the number of shells striking the target. After a strike, there is a delay of approximately three minutes before another strike can be initiated.

Fallout 4
The artillery piece can be built after recovering the artillery schematic.

Behind the scenes

 * Originally, there were two artillery pieces. The laser cannon, which can be seen in the concept art, never made it into the game.

Bugs

 * Sometimes when calling in a strike, the sound of the mortar coming in can be heard, but no explosion will follow.
 * Multiple artillery pieces in one settlement causes bugs with it proper firing. The more of them you have, the worse they work. For example: 2 pieces can take more time to start firing than one or fire the same quantity of shots. The main reason - they run consecutively, not simultaneously. After they start - first artillery slowly rotates, then fires. Then second artillery begin to rotate, and this animation takes more time than delay time between shots of one piece, while the first one freezes for the time of this animation.
 * After a fire mission request, it can happen that only 1 or 2 rounds arrive at the target area. Sometimes nothing hit the target area.
 * Stealth Boys don't protect the player character from being detected by the enemy if an artillery round hits an enemy. You get detected instantly.