Seriously? The Navy couldn’t get the ammo right?

Designed as long-range offshore fire support for a potential U.S. Marines’ amphibious landing, the stealthy Mark 51 155mm/62 (6.1”) AGSs were supposed to be the largest caliber of offshore naval gunfire support aboard a U.S. Navy warship. However, their ammunition magazines and automated loading were not designed to fit, handle, and fire U.S. Army and NATO-standard 155mm howitzer shells due to differences in the shape and size of the projectile and firing charges, thus requiring special custom GPS Long-Range Land Attack Projectiles (LRLAP) costing around $800,000+ each due to the reduction of Zumwalt-class destroyers from 32 to 3. 

Each DDG-1000 destroyer has two 155mm Advanced Gun System cannons on the forward section. These guns will be removed to make way for 12 Conventional Prompt Strike hypersonic missiles

This exorbitant cost of each shell rendered the AGSs useless for years even though the guns could, in theory, fire at 83 nautical miles (150 kilometers) at 10 rounds-per-minute with LRLAP.  A whopping 335 155mm rounds can be carried aboard each AGS, or 670 rounds for both 155mm AGSs. There is also an auxiliary storeroom separate from the automated ammunition handling system that can hold an additional 320 rounds and would require the manual transfer of the rounds to the guns’ magazines. Therefore, one Zumwalt-class destroyer has 990 rounds of 155mm AGS shells.

Once removed, if the DDG-1000s’ six 155mm AGSs will ever be resurrected in the future seems murky as the AGSs never did have much of a purpose without shells to fire. If they ever do see a resurrection, they would need a total revamp of their automated ammunition handling facilities to accommodate and fire much cheaper and plentiful 155mm U.S. Army and NATO shells and do away with the U.S. Navy’s super-expensive LRLAP shells. 

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