The US Navy


	U.S. Navy Fact Sheet MK 45 - 5-inch-gun 54/62 Caliber Guns Description Fully-automatic naval gun mount employed against surface (Anti-Surface Warfare - ASuW), air (Anti-Air Warfare - AAW), and land attack (Naval Surface Fire Support - NSFS) targets. Background The MK 45 gun was developed as a lighter weight, more easily maintained replacement for the MK 42 5”/54 caliber gun mount. It is designed to engage surface and air targets and to provide naval surface fire support for expeditionary operations. The MK 45 Mod 4 gun mount upgrade includes a longer barrel (62 caliber) that improves the gun’s effectiveness as a land attack weapon (naval surface fire support). The gun mount includes a 20 round automatic loader drum. The un's maximum firing rate is 16-20 rounds from the loader drum per minute. The rounds in the loader drum and be fired with one crewmember located at the EP-2 console below deck. Additional rounds can be accomplished by the full crew (Mount Captain, EP-2 Operator and four ammunition handlers), all of which are stationed below deck. The MK 45 gun is installed aboard DDG 51 and CG 47 class ships.

	Point Of Contact Office of Corporate Communication (00D) Naval Sea Systems Command Washington Navy Yard, D.C. 20376

	General Characteristics
	Primary Function: Fully-automatic, naval gun mount.
	Date Deployed: 1971 (Mark 45 Mod 0)
	Range: 13 nautical miles (14.9 statute miles) with conventional ammunition.
	Type Fire: 16-20 rounds per minute automatic, conventional ammunition.
	Magazine Capacity: 600 rounds conventional.
	Caliber: 5 inch 54 caliber (MK 54 Mod 1/2) barrel length of 70 inches (54 x 5”); 5 inch 62 caliber (MK 45 Mod 4 )barrel length is 310 inches (62 x 5
	Guidance System: MK 45 Gun Mount is remotely fired from the MK 160 Gun Computer System or MK 86 Gun Fire Control during normal operations
	Platforms: MK 45 Mod 2 (5”/54) - DDGs 51-80 5” 54 (1 gun mount per ship); CGs 61, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73 (2 gun mounts per ship). MK 45 Mod 4 (5”/62) – DDG 81-113AF (1 gun mount per ship); CG 52-58, 60, 62 (2 gun mounts per ship) – Other CGs including CG 59 & CG71 will receive MK 45 Mod 4 gun mounts during CG Mod overhauls (CG 59 - FY13 & CG 71 - FY15).

	Last Update: 19 October 2012