What Happened to Advanced Gun System (AGS)?
The Advanced Gun System (AGS) was a 155mm naval artillery system developed by BAE Systems for the U.S. Navy's Zumwalt-class destroyers, intended for long-range land attack. Despite its installation on all three Zumwalt ships, its specialized Long Range Land Attack Projectile (LRLAP) ammunition was canceled in 2016 due to exorbitant costs, rendering the guns unusable. As of 2024-2026, the AGS systems are being actively removed from the Zumwalt-class destroyers to make way for Conventional Prompt Strike (CPS) hypersonic missile launchers.
Quick Answer
The Advanced Gun System (AGS), designed as the primary armament for the Zumwalt-class destroyers, has been rendered obsolete. Its unique Long Range Land Attack Projectile (LRLAP) was canceled in 2016 due to per-round costs escalating to $800,000 - $1 million, leaving the guns without compatible ammunition. Consequently, the U.S. Navy began removing the AGS from the Zumwalt-class ships in 2024, with the USS Zumwalt (DDG-1000) completing its refit in early 2026 to accommodate Conventional Prompt Strike (CPS) hypersonic missile systems, signifying the definitive end of the AGS's operational role.
📊Key Facts
📅Complete Timeline13 events
Advanced Gun System (AGS) Design Initiated
The Advanced Gun System (AGS) was designed by BAE Systems for the future Zumwalt-class destroyers, with the goal of providing long-range naval gunfire support.
Shift from Vertical Gun to Conventional Turret Design
The U.S. Navy decided to abandon the truly vertical mounting design for the AGS, opting instead for a more conventional turret configuration, which allowed for the use of both guided and unguided munitions.
Lockheed Martin Selected for LRLAP Development
Lockheed Martin was selected over Raytheon to continue the development of the Long Range Land Attack Projectile (LRLAP), the specialized ammunition for the AGS.
BAE Systems Awarded $376M Contract for AGS/LRLAP
United Defense (later BAE Systems) received a contract not to exceed $376 million for the continuation of design, development, and testing of the AGS weapon system and the LRLAP projectile.
First Automated Magazine Delivered
BAE Systems delivered the first automated magazine for the 155mm Advanced Gun System to the U.S. Navy, a key component for the Zumwalt-class destroyer program.
Initial Operational Capability (IOC)
The Advanced Gun System reached its Initial Operational Capability (IOC) in 2014, as planned for the Zumwalt-class destroyers.
LRLAP Ammunition Procurement Canceled
The U.S. Navy canceled the procurement of the Long Range Land Attack Projectile (LRLAP) due to its exorbitant cost, which had risen to $800,000 - $1 million per round, effectively rendering the AGS unusable.
Zumwalt Mission Shifted Due to AGS Issues
Development issues with the AGS and the cancellation of its ammunition prompted the Navy to change the Zumwalt-class mission from a land-attack platform to a ship-killer, focusing on other weapon systems.
Navy Announces AGS Replacement with Hypersonic Missiles
The U.S. Navy officially announced its intention to replace the AGS mounts on the Zumwalt-class destroyers with modules to carry hypersonic missiles, specifically the Common-Hypersonic Glide Body (C-HGB).
USS Zumwalt Enters Dry-Dock for Modernization
The USS Zumwalt (DDG-1000) entered Huntington Ingalls Industries (HII) facilities for a major modernization, including the removal of its AGS systems and installation of hypersonic missile launchers.
AGS Removal Begins on Zumwalt-Class Ships
The U.S. Navy commenced the physical removal of the Advanced Gun Systems from the Zumwalt-class destroyers as part of their refit for new weapon systems.
Hypersonic Missile Module Installation Completed on USS Zumwalt
Installation of the advanced payload modules for Conventional Prompt Strike (CPS) hypersonic weapons was completed on the USS Zumwalt (DDG-1000).
USS Zumwalt Returns to Sea Without AGS, Equipped with Hypersonic Missiles
The USS Zumwalt (DDG-1000) departed Pascagoula for sea trials, confirming the removal of both 155mm AGS and its new armament of 12 Conventional Prompt Strike (CPS) hypersonic missiles.
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🔍Deep Dive Analysis
The Advanced Gun System (AGS) was conceived in the context of the United States Navy's need for long-range naval gunfire support following the retirement of battleships in the early 1990s. Designed by BAE Systems (formerly United Defense) for the Zumwalt-class destroyers, the 155mm/62 (6.1-inch) Mark 51 AGS was intended to provide precision land attack capabilities at ranges exceeding 80 nautical miles. Each of the three Zumwalt-class ships was equipped with two AGS mounts, featuring fully automated ammunition handling and a high rate of fire of 10 rounds per minute.
The primary ammunition for the AGS was the Long Range Land Attack Projectile (LRLAP), a rocket-assisted, GPS-guided munition. Development of the LRLAP was a significant undertaking, with Lockheed Martin selected for its continued development in 2003. However, a critical turning point occurred in November 2016 when the U.S. Navy canceled the LRLAP procurement. The cost per round had soared to an unsustainable $800,000 to $1 million, largely due to the drastic reduction in the planned number of Zumwalt-class ships from 32 to just three. This made the specialized ammunition prohibitively expensive, effectively rendering the installed AGS guns unusable as no other existing 155mm ammunition was compatible without extensive and costly modifications.
The consequences of the LRLAP cancellation were profound. The Zumwalt-class destroyers, originally designed around their land-attack gun systems, were left without their primary offensive armament. This prompted a re-evaluation of the ships' mission, shifting their focus from land attack to surface warfare. In April 2021, the Navy announced plans to replace the AGS with a new weapon system: hypersonic missiles.
As of 2026, the AGS is in the process of being completely phased out. The Navy began removing the AGS from the Zumwalt-class destroyers starting in 2024. This extensive modernization effort involves replacing the two 155mm AGS mounts with four large-diameter vertical launch tubes capable of housing 12 Conventional Prompt Strike (CPS) hypersonic missiles. The USS Zumwalt (DDG-1000) completed its dry-dock period and returned to sea for trials in January 2026, becoming the first U.S. Navy vessel equipped with these hypersonic weapons, with its AGS systems confirmed removed. The other two Zumwalt-class ships are expected to undergo similar modifications. This marks the definitive end of the Advanced Gun System's brief and largely non-operational life as a naval artillery system.
What If...?
Explore alternate histories. What if Advanced Gun System (AGS) made different choices?