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5"/31 caliber gun

The 5"/31 caliber gun (spoken "five-inch-thirty-one-caliber") were used in the secondary batteries of the United States Navy's "New Navy" protected cruiser Chicago and later mounted in Panther during the Spanish–American War.[1]

5"/31 caliber Mark 1 Naval Gun
TypeNaval gun
Place of originUnited States
Service history
In service1889–1910
Used by United States Navy
WarsSpanish–American War
Production history
DesignerBureau of Ordnance
ManufacturerU.S. Naval Gun Factory
No. built2
VariantsMark 1 Mod 0 and 1
Mass6,190 lb (2,810 kg) (without breech)
Length159.97 in (4.063 m) Mark 1 Mod 1
Barrel length153.97 in (3.911 m) bore (31 calibers)

Shell50 lb (23 kg)
Caliber5 inches (127 mm)
Traverse−150° to +150°
Rate of fire6 rounds per minute
Muzzle velocity2,300 ft/s (700 m/s)
Maximum firing range16,000-yard (14,630 m) at 30° elevation



Mark 1, Nos. 1 and 2, were 31 calibers and two of the first steel tube guns that were built entirely in the United States. They were trunnioned guns, no liners and that fired bag ammunition. After the Spanish–American War was over they were modified to Mod 1 in 1901. A liner was inserted in the breech end and the trunnions were cut off. The Mod 1 consisted of tube, jacket, and 9 hoops. After these changes the gun was able to use the same ammunition as the later Mark 2 5-inch gun.[1][2]

Naval ServiceEdit

Ship Gun Installed Gun Mount
USS Chicago (1885) Mark 1 Mod 0: 2 × 5"/30 caliber (removed April 1898) Mark 1: 2 × single mounting with gravity return
USS Panther (1889) Mark 1 Mod 0: 2 × 5"/30 caliber (installed July 1898) Unknown


  1. ^ a b "United States of America 5"/31 (12.7 cm) Mark 1". Navweaps. 13 March 2007. Retrieved 22 May 2016.
  2. ^ Friedman, Norman (2011). Naval Weapons of World War One. Seaforth Publishing. p. 183. ISBN 978 1 84832 100 7.

External linksEdit