The 5"/50 caliber gun (spoken "five-inch-fifty-caliber") was the first long barrel 5-inch (127 mm) gun of the United States Navy and was used in the secondary batteries of the early Delaware-class dreadnought battleships, various protected cruisers, and scout cruisers. They were also refitted in the secondary batteries of the armored cruiser New York and the New Orleans-class protected cruisers. They were later used on cargo ships, store ships and unclassified auxiliaries during World War II as well as in emergency coastal defense batteries.[1]

Chattanooga, 5"/50 caliber deck gun, probably port side forward.
Type
  • Naval gun
  • Coastal gun
  • Place of originUnited States
    Service history
    In service1904
    Used by United States Navy
    Wars
    Production history
    DesignerBureau of Ordnance
    Designed1900
    ManufacturerU.S. Naval Gun Factory
    No. built
    • Mark 5: 87 (Nos. 200–286)
    • Mark 6: 64 (Nos. 293–356)
    VariantsMark 5 Mods 0–3, Mark 6 Mods 0–2
    Specifications
    Mass
    • Mark 5: 10,294 lb (4,669 kg) (with breech)
    • Mark 6: 10,550 lb (4,790 kg) (with breech)
    LengthMarks 5 and 6: 255.65 in (6,494 mm)
    Barrel lengthMarks 5 and 6: 250 in (6,400 mm) bore (50 calibers)

    Shell
    • Mark 5: 60 lb (27 kg) armor-piercing
    • Mark 6: 50 lb (23 kg) armor-piercing
    Caliber5 in (127 mm)
    Elevation
    • Mark 9: −10° to +15°
    • Mark 12: −10° to +25°
    Traverse−150° to +150°
    Rate of fire6–8 rounds per minute
    Muzzle velocity
    • 50lb:3,000 ft/s (910 m/s)
    • 60lb:2,700 ft/s (820 m/s)
    Maximum firing range19,000 yd (17,000 m) at 25.3° elevation

    Design

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    The Mark 5, Nos. 200 – 286, was a 50 caliber naval gun of a simplified construction by combining the breech piece along with the chase hoop into one long tube that was shrunk on from the muzzle. Mod 1 was a Mod 0 gun that was relined with a conical nickel-steel liner and an additional gun-steel chase hoop that extended to the muzzle that was secured by a nickel-steel locking ring. Mod 2, gun No. 280, had a slightly different liner with Mod 3, gun No. 245, was a Mod 0 gun with its gun-steel tube replaced with a nickel-steel tube with a gun-steel chase hoop added that extended all the way to the muzzle. The Mod 3 gun had a longer chase hoop and shorter jacket compare to Mods 1 and 2.[1][2]

    The Mark 6, gun Nos. 293 – 356, was the bag-ammunition equivalent to the Mark 5 gun. Mod 0, Nos. 323 – 356, had a single jacket constructed of nickel-steel, that replaced the jacket, chase hoop and locking ring of the Mark 5. Mod 1, Nos. 293 – 306 and 308, was built of gun-steel with a chamber of a different design with some external differences to fit it onto different mountings. The Mod 2, Nos. 307 and 309 – 322, had the same chamber as the Mod 0 but was otherwise almost identical to the Mod 1.[1][2]

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    Ship Gun Installed Gun Mount
    USS Delaware (BB-28) Mark 6 Mod 0: 14 × 5"/50 caliber (Nos. 343–356) Mark 9 and 12
    USS North Dakota (BB-29) Mark 6 Mod 0: 14 × 5"/50 caliber (Nos. 329–342) Mark 9 and 12
    USS New York (ACR-2) Mark 6 Mod 1: 10 × 5"/50 caliber (Nos. 295–304) (1907 refit) Unknown
    USS Denver (C-14) Mark 5: 10 × 5"/50 caliber Unknown
    USS Des Moines (C-15) Mark 5: 10 × 5"/50 caliber Unknown
    USS Chattanooga (C-16) Mark 5: 10 × 5"/50 caliber Unknown
    USS Galveston (C-17) Mark 5: 10 × 5"/50 caliber Unknown
    USS Tacoma (C-18) Mark 5: 10 × 5"/50 caliber Unknown
    USS Cleveland (C-19) Mark 5: 10 × 5"/50 caliber Unknown
    USS Chester (CS-1) Mark 6 Mod 0: 2 × 5"/50 caliber (Nos. 323–324) Unknown
    USS Birmingham (CS-2) Mark 6 Mod 0: 2 × 5"/50 caliber (Nos. 325–326) Unknown
    USS Salem (CS-3) Mark 6 Mod 0: 2 × 5"/50 caliber (Nos. 327–328) Unknown
    USS New Orleans (CL-22) Mark 5: 10 × 5"/50 caliber (1904 and 1907 refits) Unknown
    USS Albany (CL-23) Mark 5: 10 × 5"/50 caliber (1904 and 1907 refits) Unknown

    The 5-inch/50 caliber gun was also used on cargo ships, store ships and unclassified auxiliaries during World War II.[1]

    Notes

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    1. ^ a b c d Navweaps 2008.
    2. ^ a b Friedman 2011, p. 184–185.

    References

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    • Friedman, Norman (2011). Naval Weapons of World War One. Seaforth Publishing. ISBN 978-1-84832-100-7.
    • "United States of America 5"/50 (12.7 cm) Mark 5 and Mark 6". Navweaps. 12 February 2008. Retrieved 20 October 2016.
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