5-inch/51-caliber gun

5"/51 caliber gun
5"/51 caliber gun
	5"/51 caliber Mark 8 gun on starboard forecastle of USS Texas, March 1914
Type	Naval gun; Coastal defence; Coast Guard gun;
Place of origin	United States
Service history
In service	1911–c. 1947
Used by	United States Navy; United States Marine Corps; United States Coast Guard; Royal Navy;
Wars	World War I; World War II;
Production history
Designer	Bureau of Ordnance
Designed	1910
Manufacturer	Naval Gun Factory; American & British Mfg. Co. (Nos. 702–727); Watervliet Arsenal (Nos. 768–787); Liberty Ordnance Co. (Nos. 898–1043); Four Lakes Ordnance Co. (Nos. 1157–1356); Midvale Steel (Nos. 1457–1504 and 1705–1716); American Can Co. (Nos. 1505–1518);
No. built	Mark 7: 93 (Nos. 357–449); Mark 8: 1004 (NGF 539 Nos. 450-unknown)(see builders); (No Nos. 1357–1456, 1519–1604 or 1633–1704); Mark 9: 3 (Unknown Nos.); Mark 14: relined Mark 8s; Mark 15: enlarged chamber Mark 14s;
Variants	Marks 7, 8, 9, 14, 15
Specifications
Mass	Mark 7: 11,274 lb (5,114 kg) (with breech); Mark 8: 10,834 lb (4,914 kg) (without breech); Mark 8: 11,300 lb (5,100 kg) (with breech); Mark 9: 10,824 lb (4,910 kg) (without breech); Mark 9: 11,375 lb (5,160 kg) (with breech);
Length	261.25 in (6,636 mm)
Barrel length	255 in (6,500 mm) bore (51 calibers)
Shell	50–55.18 lb (22.68–25.03 kg)
Caliber	5 in (127 mm)
Breech	side swing Welin-type
Elevation	P13: -10° to +20° (late version); P15: -15° to +20°; Mark 18: -8.5° to +25°;
Traverse	up to 360° depending on location
Rate of fire	8-9 rounds per minute
Muzzle velocity	3,150 ft/s (960 m/s) (full charge); 2,300 ft/s (700 m/s) (reduced charge);
Effective firing range	17,000 yd (16,000 m) at 20° elevation
Maximum firing range	20,142 yd (18,418 m) at 45° elevation (World War II ammunition)

5"/51 caliber guns (spoken "five-inch-fifty-one-caliber") initially served as the secondary battery of United States Navy battleships built from 1907 through the 1920s, also serving on other vessels. United States naval gun terminology indicates the gun fired a projectile 5-inch (127 mm) in diameter, and the barrel was 51 calibers long.^[1]

^ Fairfield 1921 p. 156

[1] Fairfield 1921 p. 156

[1]

5"/51 caliber gun
5"/51 caliber Mark 8 gun on starboard forecastle of USS Texas, March 1914
Type	Naval gun Coastal defence Coast Guard gun
Place of origin	United States
Service history
In service	1911–c. 1947
Used by	United States Navy United States Marine Corps United States Coast Guard Royal Navy
Wars	World War I World War II
Production history
Designer	Bureau of Ordnance
Designed	1910
Manufacturer	Naval Gun Factory American & British Mfg. Co. (Nos. 702–727) Watervliet Arsenal (Nos. 768–787) Liberty Ordnance Co. (Nos. 898–1043) Four Lakes Ordnance Co. (Nos. 1157–1356) Midvale Steel (Nos. 1457–1504 and 1705–1716) American Can Co. (Nos. 1505–1518)
No. built	Mark 7: 93 (Nos. 357–449) Mark 8: 1004 (NGF 539 Nos. 450-unknown)(see builders) (No Nos. 1357–1456, 1519–1604 or 1633–1704) Mark 9: 3 (Unknown Nos.) Mark 14: relined Mark 8s Mark 15: enlarged chamber Mark 14s
Variants	Marks 7, 8, 9, 14, 15
Specifications
Mass	Mark 7: 11,274 lb (5,114 kg) (with breech) Mark 8: 10,834 lb (4,914 kg) (without breech) Mark 8: 11,300 lb (5,100 kg) (with breech) Mark 9: 10,824 lb (4,910 kg) (without breech) Mark 9: 11,375 lb (5,160 kg) (with breech)
Length	261.25 in (6,636 mm)
Barrel length	255 in (6,500 mm) bore (51 calibers)

Shell	50–55.18 lb (22.68–25.03 kg)
Caliber	5 in (127 mm)
Breech	side swing Welin-type
Elevation	P13: -10° to +20° (late version) P15: -15° to +20° Mark 18: -8.5° to +25°
Traverse	up to 360° depending on location
Rate of fire	8-9 rounds per minute
Muzzle velocity	3,150 ft/s (960 m/s) (full charge) 2,300 ft/s (700 m/s) (reduced charge)
Effective firing range	17,000 yd (16,000 m) at 20° elevation
Maximum firing range	20,142 yd (18,418 m) at 45° elevation (World War II ammunition)