6-inch/47-caliber gun

6-inch/47-caliber gun
Three forward turrets and empty cartridge cases on USS Brooklyn (CL-40) after she had bombarded Licata, Sicily, during the early hours of the Allied invasion, 10 July 1943
Type	Naval gun
Place of origin	United States
Service history
In service	1936–1979 (US service) 1951–1982 (Argentine service) 1951–1973 (Brazilian service) 1951–1992 (Chilean service)
Used by	United States Navy  Argentine Navy  Brazilian Navy  Chilean Navy
Wars	World War II Korean War Vietnam War Falklands War
Production history
Designed	Mark 16: 1932 Mark 16DP: 1943 Mark 17: 1933
Variants	Mark 16/16DP and Mark 17
Specifications
Mass	Mark 16/16DP: 6.5 short tons (13,000 lb; 5,897 kg) Mark 17: 5.24 short tons (10,480 lb; 4,754 kg)
Length	Mark 16/16DP: 300 in (7.6 m) overall length Mark 17: 289 in (7.3 m) overall length
Barrel length	282.3 in (7.17 m) bore (47 calibers)
Shell	Mark 16: 130 lb (59 kg) armor-piercing Mark 35 (super heavy) 105 lb (48 kg) HC (high capacity) Mark 34/39 Mark 17: 105 lb Common Mark 28
Caliber	6 inches (152 mm)
Recoil	Mark 16/16DP: 21 in (53 cm) Mark 17: 24 in (61 cm)
Elevation	Mark 16: −5° to +40°, later modified to +60° Mark 16DP: −5° to +78° Mark 17: −10° to +20°
Traverse	−150° to +150° (all variants)
Rate of fire	Mark 16: 8–10 rounds per minute Mark 16DP: 12 rounds per minute Mark 17: 5–8 rounds per minute
Muzzle velocity	Mark 16/16DP: Full charge 2,500 ft/s (760 m/s) AP Mark 35 2,665 ft/s (812 m/s) HC Mark 34 Reduced charge 2,050 ft/s (620 m/s) AP Mark 35 2,225 ft/s (678 m/s) HC Mark 34 Mark 17: 2,800 ft/s (850 m/s) Common Mark 28
Effective firing range	Mark 16/16DP: 20,000-yard (18,288 m) at 22.3° elevation (130-lb AP shell) Mark 17: 19,800-yard (18,105 m) at 20° elevation (105-lb Common shell)
Maximum firing range	Mark 16/16DP: 26,118-yard (23,882 m) at 47.5° elevation (130-lb AP shell)

The 6-inch/47-caliber Mark 16 gun was used in the main batteries of several pre-war and World War II US Navy light cruisers. They were primarily mounted in triple turrets and used against surface targets. The Mark 16DP gun was a dual-purpose fitting of the Mark 16 for use against aircraft as well as surface ships. It was installed in the postwar Worcester-class light cruisers and the anti-aircraft gunnery training ship Mississippi.

The Mark 17 gun was a variation of the Mark 16 to use bagged charges; this was only used in the Erie-class gunboat in a single-pedestal mount.