vertical gun system it would only have been capable of firing guided munitions; the turret mounting allows the use of unguided munitions as well if any are developed for it. AGS is not designed to use the same munitions as other artillery, so each type of munition must be designed and manufactured specifically for AGS. Long Range Land Attack Projectile (LRLAP) ammunition for AGS was to be a major advance. LRLAP featured separate projectile and propellant portions and was to be highly precise, with a circular error probable (CEP) of or less. Lockheed Martin's flight test of the munition in July 2005 had a reported a flight distance of . However, LRLAP procurement was cancelled in 2016 and the Navy had no plan to replace it. By early 2021, the Navy was exploring replacing the AGS on Zumwalt ships with modules to carry hypersonic missiles. In March 2022, it was announced that both AGS would be removed from Zumwalt destroyers to enable installation of tubes to accommodate Common-Hypersonic Glide Body missiles. The switch will begin in late 2023 as the ships undergo maintenance periods. AGS was developed and produced by BAE Systems Armaments Systems (formerly United Defense) for the Zumwalt-class destroyer of the United States Navy. The first magazine was delivered to the U.S. Navy on 25 May 2010. Description The AGS uses the same 155 mm caliber as most American field artillery forces, although it is unable to fire the same ammunition due to differences in the size and shape of both projectile and firing charges. The gun barrel is 62 calibers long, and is able to fire the entire magazine (300+ rounds) with an average rate of fire of ten rounds per minute using a water cooled barrel. The AGS is mounted in a turret specifically designed for the Zumwalt class destroyer with fully automated ammunition supply and operation. The turret itself is designed to be stealthy, allowing for the entire length of the barrel to be enclosed and hidden from radar when not firing. A primary advantage of the AGS over the existing 127 mm Mark 45 5" gun which equips most major surface combatants of the US Navy was to be its increased capability for supporting ground forces and striking land targets. With a 10-round per minute capacity, it would have had the ability to deliver the firepower of a battery of six 155 mm howitzers.