Artillery Piece (Fallout 4)

The artillery piece is a constructible settlement item featured in Fallout 4.

Characteristics
The artillery piece is a mortar capable of high precision, high accuracy, and highly-damaging fire. However, has a maximum range of approximately 5 squares as viewed on the Pip-Boy's world map. Artillery strikes can be called down by throwing an artillery smoke grenade within range of a placed cannon. Having more manned pieces allows for more hits during a single salvo: each piece affords five shots.

Behind the scenes
Artillery seems to be heavily based on the 12-inch coast defense mortar, which was in service from the late 19th to the mid 20th centuries.

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 consequentially, 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.

More than 2 pieces causes even more troubles - very long delay time before starting fire (each of them have to rotate first), longer timeout between shots or not firing at all (while radio freedom plays all stages - "...saw your flare", "...firing", "...mission complete").

It seems that "firemission" of artillery has the limited time. So if you have many pieces - they all spend most of this limit for rotations. One by one before their first shot... The best option for relible work to put one piece of artillery in each settlement. Maximum two - most of the times two pieces work better, sometimes worse.