MK 110 57 mm Gun

Also known as

57mm MK 110 Gun Mount
57 mm MK 110 Gun Mount
MK110
Bofors 57Mk3

The MK 110 57 mm Gun is a fully automatic naval gun mount derived from BAE Bofors' 57 mm Mk3 design and assembled in Louisville, Kentucky for U.S. service. The U.S. Navy fact file says it fires up to 220 rounds per minute, carries 120 ready rounds, and is fitted to Littoral Combat Ships and Coast Guard National Security Cutters.

MK 110 57 mm Gun, 57 mm naval gun, Naval Systems

Image source: 210709-N-RL695-1119

Profile / Specs

Profile

Origin: Sweden
Built by: BAE Systems BoforsBAE Systems Land and Armaments L.P.
Built in: SwedenUnited States
Type: 57 mm naval gun
Service note: 1995-present
Designed: 1995
Unit cost: $8,929,876 (2015 contract modification for one MK 110 Mod 0 gun weapon system)

naval maritime surface warfare

Specifications

Caliber: 57 mm
Rate of fire: 220 rounds per minute
Range: 17,000 m (9.1 nautical miles)
Ready rounds: 120
Barrel length: 57 mm / 70 calibers
Platform fit: LCS and USCG WMSL class ships

Ship Platforms

Navy photo coverage shows the MK 110 mounted on USS Sioux City during maintenance in 2021.

Firing weapon

Weapon type

Firing evidence

Freedom-class Littoral Combat Ship, Freedom-variant littoral combat ship, Naval Systems

Freedom-class Littoral Combat Ship

Freedom-variant littoral combat ship

The Navy photo caption for USS Sioux City shows sailors conducting maintenance on a 57mm MK 110 gun aboard the ship.

Sources: 210709-N-RL695-1119

Timeline

MK 110 57 mm Gun Key Events

Jan 1, 1995
Current 57 mm Mk3 version designed
The U.S. Navy fact file says the current version of the gun was designed in 1995 as part of the BAE Bofors 57 mm Mk3 line.
Sources: MK 110 57 mm Gun
Jan 1, 2000
Swedish service begins
The Navy fact file says the 57 mm Mk3 entered Swedish service in 2000 before U.S. shipboard adoption.
Sources: MK 110 57 mm Gun
Jan 1, 2008
U.S. service adoption
The Navy fact file says the MK 110 was selected for U.S. Navy Littoral Combat Ships and U.S. Coast Guard National Security Cutters.
Sources: MK 110 57 mm Gun

Service And Conflict Use

Service History

In service: Installed on U.S. Navy Littoral Combat Ships and U.S. Coast Guard National Security Cutters; the Navy fact file lists one 57 mm mount per ship on LCS and WMSL classes.
Used by: United States Navy, United States Coast Guard

Media

MK 110 57 mm Gun Images

MK 110 57 mm Gun, 57 mm naval gun, Naval Systems - view 1 — Source: 210512-N-RL695-1411

MK 110 57 mm Gun, 57 mm naval gun, Naval Systems - view 2 — Source: 210512-N-RL695-1387

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Sources

MK 110 57 mm GunPublisher: U.S. Navy | Note: Supports the MK 110's 57 mm caliber, 220 rounds per minute rate of fire, 17,000 meter / 9.1 nautical mile range, 120-round magazine, 1995 design date, 2000 Swedish introduction, 2008 U.S. service, and BAE Bofors background. | Accessed: 2026-06-27 Contracts For Dec. 2, 2015 - Department of WarPublisher: U.S. Department of Defense | Note: Supports the 2015 award for one MK 110 Mod 0 gun weapon system and the contract value used for the MK 110 unit cost. | Accessed: 2026-06-27 210709-N-RL695-1119Publisher: U.S. Navy | Note: Supports image provenance and the USS Sioux City / MK 110 relationship in July 2021. | Accessed: 2026-06-27 210512-N-RL695-1411Publisher: U.S. Navy | Note: Supports image provenance for a second USS Sioux City photo of the MK 110 gun in maintenance context. | Accessed: 2026-06-27 210512-N-RL695-1387Publisher: U.S. Navy | Note: Supports image provenance for a third USS Sioux City photo showing the MK 110 mount during maintenance. | Accessed: 2026-06-27