Developed as a joint project with the United Kingdom, which called it the QF 3-inch Mark N1 gun, it had a water-cooled barrel combined with an automatic loader to deliver high rates of fire.

The British mountings, known as Mark 6 in the Royal Navy, were to a different design and though also complex and subject to feed problems were more effective.

The 3-inch round was chosen because it was the smallest caliber ammunition that could be fitted with a VT radar proximity fuze.

The twin barrel mount was believed to be more effective against faster aircraft and guided missiles than the single mounted 5"/54 caliber Mark 42 gun, hence, the single barrel version of the Mark 26 never saw service use.

The Mark 23 was the initial prototype on USS Carpenter to test the fully automatic firing of the artillery.