5-inch/40-caliber gun

The Mark 2, Nos. 3 – 70, was a 40 caliber naval gun that fired semi-fixed ammunition. The Mark 2 consisted of tube, jacket, and 2 hoops, being hooped to {{convert|68.5|in}} from the muzzle. The Mod 1 had different exterior dimensions for the hoops and chase and was primarily intended to be used with the Mark 2 Mods 1 and 4 mounts. Mod 2 had a cylindrical jacket that was {{convert|15.5|in}} in diameter for {{convert|2.75|in}} to the rear of the mounting threads. It was intended for the Mark 2 Mods 1 and 4 and Mark 3 Mods 1 and 6 mounts. Mod 3 was the same as the Mod 2 but without the cylindrical section. It was designed to use the Mark 2 Mods 1, 2, 4, and 5 and the Mark 3 Mods 1, 4, 6, and 9 mounts. The Mod 4 only differed from the Mark 3 in that it had a muzzle bell. Mod 5, gun No. 39, was an experimental gun that had {{convert|25|in}} cut off of the muzzle, making it a 35-caliber gun. It also had a locking hoop that extended the whole length of the chase hoop to help balance the gun. The Mod 6 was a Mod 4 gun that had been modified for use in the 5-inch Mark 8 Mods 4, 13, and 14 mounts. The breech was turned down a {{convert|0.25|in}} to {{convert|16.25|in}} for {{convert|13.435|in}} from the face of the breech with the front part of the thread for the sleeve cut away. The Mod 7 gun was a Mod 2, 3, or 4 that had a conical nickel-steel liner and a Mod 8 was a Mod 6 gun also with a conical nickel-steel liner. The first gun that was delivered in October 1890 was gun No. 5. The Mark 2 was intended for use on battleships and cruisers, such as {{USS|Olympia|C-6|2}}, {{sclass|Cincinnati|cruiser|0}} protected cruisers, {{sclass|Montgomery|cruiser|0}} unprotected cruisers, and auxiliary cruisers such as {{USS|Yosemite|1894|2}}.{{sfn|Navweaps|2016}}{{sfn|Friedman|2011|p=183}}

The Mark 3, gun Nos. 87–199, 287–292, were first delivered in January 1897. The Mark 3 was also a semi-fixed ammunition gun that was designed for use on cruisers and battleships. The Mark three was constructed of a tube, jacket and two hoops, all of gun steel with a side-swing carrier type breech. Mod 1 used a different jacket with a locking hoop forward of the slide cylinder. Mod 2 was a Mod 0 or Mod 1 gun relined using a conical nickel-steel liner. Gun No. 104 was converted into and experimental Mod 3 gun from a Mod 0, being cut down to 25-caliber or {{convert|75.39|in}}, for use as an anti-aircraft gun. The muzzle end was cut off and a conical nickel-steel liner installed, this gave it the same characteristics as a 5″/25 caliber Mark 10 anti-aircraft gun. The gun later ruptured during testing. The muzzle of gun No. 174, mounted on the battleship {{USS|Kearsarge|BB-5|2}}, also had its muzzle blow off.{{sfn|Navweaps|2016}}{{sfn|Friedman|2011|p=183}}

The Mark 4, guns No. 71–86, delivered in April 1896, were derived from the Mark 2 but {{convert|0.17|in}} longer and consequent differences in slide surface and other externals. Mod 1 added a nickel-steel tube and hoops that the Mod 0 didn't have and the Mod 3 was the Mod 1 relined with a nickel-steel liner. With the Mod 4 an attempt was made to thread the gun to fit the Mark 2 Mod 4 mount but wasn't used. This gun was designed to arm small cruisers and many were used to arm auxiliaries during WW I.{{sfn|Navweaps|2016}}{{sfn|Friedman|2011|p=183}}

|Mark 3: 4 × 5″/40 caliber (Nos. 161–164)

|Unknown

|}

Marks 2–4 were used on many auxiliaries during World War I.{{sfn|Friedman|2011|p=183}}

{{Reflist|2}}

• {{cite book

| first=Norman

| last=Friedman

| author-link=Norman Friedman

| url=https://books.google.com/books?id=yh3OAwAAQBAJ

| title=Naval Weapons of World War One

| publisher=Seaforth Publishing

| year=2011

| isbn=978-1-84832-100-7

}}

• {{cite web

|url=http://www.navweaps.com/Weapons/WNUS_5-40_mk2.htm

|title=United States of America 5″/40 (12.7 cm) Marks 2, 3 and 4

|publisher=Navweaps

|date=12 March 2016

|access-date=20 October 2016

|ref={{sfnRef|Navweaps|2016}}

}}

{{Commons category}}

• [http://www.gwpda.org/naval/usn14gun.htm Bluejackets Manual, 1917, 4th revision: US Navy 14-inch Mark 1 gun]

{{WWIUSNavalWeapons}}

{{DEFAULTSORT:5 40 Caliber Gun}}

Category:Naval guns of the United States

Category:127 mm artillery