Mark 55/12 Naval Cannon – Prototype Heavy Gun System

The Mark 55/12 is a prototype 305 mm (12-inch) single-barrel naval cannon developed by the U.S. Navy for long-range surface engagement. Designed to deliver devastating firepower with pinpoint accuracy, this weapon excels at precise, high-impact strikes against enemy warships, fortifications, or strategic land targets.

Despite its relatively short /12 caliber barrel, the Mark 55/12 uses advanced propellants and smart shell technology to compensate for low muzzle velocity, enabling very long-range precision strikes through high trajectory and fast fire control systems.

(Footage by 'Anonymous' from [CLASSIFIED] in storage, first prototype)

(A photograph from drone used for visual video footage for testing conducted for the experimental cannon)

If you played 'Modern Warships' you probably know or heard of this ;)