5-inch/54-caliber Mark 45 gun

In sustained firing operations (Mode III), the gun is operated by a six-person crew: a gun captain, a panel operator, and four ammunition loaders, all located below decks. In fully automatic non-sustained firing operations (Mode IV), 20 rounds can be fired without any personnel inside the mount, using an [[autoloader]].

In sustained firing operations (Mode III), the gun is operated by a six-person crew: a gun captain, a panel operator, and four ammunition loaders, all located below decks. In fully automatic non-sustained firing operations (Mode IV), 20 rounds can be fired without any personnel inside the mount, using an [[autoloader]].

In 2024–2025, U.S. Navy destroyers in the Red Sea increasingly employed the Mk 45 gun to defend themselves and merchants against one-way attack drones, launched by the Houthi rebels from Yemen.{{cite web | url=https://news.usni.org/2025/01/30/crew-of-uss-stockdale-shot-down-houthi-drones-with-5-inch-gun-says-admiral | title=Crew of USS Stockdale Shot Down Houthi Drones with 5-Inch Gun, Says Admiral | date=30 January 2025 }}

In 2024–2025, U.S. Navy destroyers in the Red Sea increasingly employed the Mk 45 gun to defend themselves and merchants against one-way attack drones, launched by the Houthi rebels from Yemen during the [[Red Sea crisis]].{{cite web | url=https://news.usni.org/2025/01/30/crew-of-uss-stockdale-shot-down-houthi-drones-with-5-inch-gun-says-admiral | title=Crew of USS Stockdale Shot Down Houthi Drones with 5-Inch Gun, Says Admiral | date=30 January 2025 }}

On 19 April 2026, the US seized the Iran-flagged cargo ship ''[[Touska]]'' after it attempted to breach the [[2026 United States naval blockade of Iran|2026 US naval blockade of Iran]].{{Cite web |date=2026-04-19 |title=Iranian ship seized by US Navy after attempting to pass through Strait of Hormuz |url=https://www.jpost.com/middle-east/iran-news/article-893549 |access-date=2026-04-19 |website=The Jerusalem Post |language=en}} The vessel, almost {{Convert|900|ft}} long, was en route to [[Bandar Abbas]]. It was warned by the guided missile destroyer {{United States Ship|Spruance|DDG-111|6}} over a six hour period before the destroyer fired several rounds from its 5-inch/54-caliber Mark 45 gun into the engine room, disabling it. It was then seized by the [[31st Marine Expeditionary Unit]] in the Gulf of Oman.{{Cite news |last= |first= |date=April 19, 2026 |title=Trump says US seizes Iranian-flagged cargo ship near Strait of Hormuz that tried to pass blockade |url=https://thehill.com/homenews/ap/ap-international/ap-iran-doubles-down-on-closing-the-strait-of-hormuz-as-the-ceasefire-inches-toward-expiration-2/mlite/ |access-date= |agency=[[Associated Press]]|publisher=The Hill |language=en-US |issn=}}{{Cite news |title=U.S. Forces Disable Vessel Attempting to Enter Iranian Port, Violate Blockade |url=https://x.com/centcom/status/2045969284690788615 |work=[[United States Central Command]] |publisher=[[X (social network)]]}} Iran described the seizure as a [[2026 Iran war ceasefire|US-Iran truce]] violation.{{Cite web |date=2026-04-20 |title=Iran Calls US Seizure Of Cargo Ship Near Hormuz "Piracy, Ceasefire Violation|url=https://www.ndtv.com/world-news/us-iran-israel-war-iran-calls-us-seizure-of-cargo-ship-near-hormuz-piracy-ceasefire-violation-middle-east-conflict-11381147 |access-date=2026-04-20 |agency=Associated Press|publisher=NDTV |language=en}}

== Ammunition ==

== Ammunition ==