Question: In what year was the US naval gun designed for the battleships to help Argentina counter Brazil's two "Minas Geraes"- class battleships?

Context articles: 16&quot;/45 caliber Mark 6 gun
Type H/PJ38 130 mm naval gun
12&quot;/50 caliber gun (Argentina)
Minas Geraes-class battleship
Brazilian cruiser Bahia
5&quot;/38 caliber gun
Brazilian battleship Minas Geraes
BL 14 inch Mk VII naval gun
Rivadavia-class battleship
Type 3 120 mm 45 caliber naval gun

The 16"/45 caliber Mark 6 gun is a naval gun designed in 1936 by the United States Navy for their Treaty battleships.
 It was first introduced in 1941 aboard their "North Carolina"-class battleship s, replacing the originally intended 14"/50 caliber Mark B guns and was also used for the follow-up "South Dakota" class.
 These battleships carried nine guns in three three-gun turrets.
 The gun was an improvement to the 16"/45 caliber guns used aboard the "Colorado" class , and the predecessor to the 16"/50 caliber Mark 7 gun used aboard the "Iowa" class .
The H/PJ38 is a new single barrel 130 mm gun of the Chinese Navy introduced on the Type 052D destroyer.
 Designed by the Zhengzhou Mechanical-Electrical Engineering Research Institute (郑州机电工程研究所, also known as the 713th Research Institute of the 7th Academy) and manufactured by Inner Mongolia 2nd Machinery Manufacturing Factory (内蒙第二机械制造厂), the H/PJ-38 130 mm naval gun was developed from reverse engineering of Soviet AK-130 twin 130 mm naval gun, which was carried out by the same two establishments.
 The general designer of the H/PJ-38, Chen Dingfeng (陈汀峰), was also the general designer of all models of Type 79 100 mm naval gun, all models of Type 210 100 mm naval gun, and the H/PJ26 76 mm naval gun.
 Chen was recalled from retirement to complete the H/PJ38 single barrel 130 mm naval gun.
 When the Soviet AK-130 was first successfully copied by Chinese developers, the Chinese navy was unsatisfied and decided not to let the AK-130 into production, despite all performance parameters being met.
 Because the AK-130 was judged out-of-date by the Chinese Navy, the H/PJ38 program was created in 2005.
 The H/PJ38 130 mm single barrel naval gun is considered more powerful and more reliable than other smaller caliber naval guns currently in Chinese service, and as with naval guns on most warships, it is installed in front of the VLS.
The 12"/50 caliber "Bethlehem" gun was a US naval gun designed in 1910 as the main armament for the Argentine Navy’s dreadnought battleships of the "Rivadavia" class .
The "Minas Geraes" class, spelled "Minas Gerais" in some sources, consisted of two battleships built for the Brazilian Navy in the early twentieth century.
 Named "Minas Geraes" and "São Paulo" , the ships were intended to be Brazil's first step towards becoming an international power, and they consequently initiated a South American naval arms race.
Bahia was the lead ship of a two-vessel class of cruisers built for Brazil by the British company Armstrong Whitworth.
 In November 1910, just six months after her commissioning, crewmen aboard "Bahia", "Marechal Deodoro" , "Minas Geraes" , and "São Paulo" mutinied, beginning the "Revolta da Chibata" (Revolt of the Lash).
 During the four-day rebellion, Brazil's capital city of Rio de Janeiro was held hostage by the possibility of a naval bombardment, leading the government to give in to the rebel demands, which included the abolition of flogging in the navy.
 During the First World War, "Bahia" and her sister ship "Rio Grande do Sul" were assigned to the "Divisão Naval em Operações de Guerra" (Naval Division in War Operations), the Brazilian Navy's main contribution in that conflict.
 Based out of Sierra Leone and Dakar, the squadron escorted convoys through an area believed to be heavily patrolled by U-boats.
The Mark 12 5"/38 caliber gun was a US naval gun.
 The gun was installed into Single Purpose and Dual Purpose mounts used primarily by the US Navy.
 On these 5" mounts, Single Purpose (SP) means that the mount is limited to 35° elevation with no provision for AA shell fuze setters, and is designed to fire at surface targets only, while Dual Purpose (DP) means that it is designed to be effective against both surface and aircraft targets because it can elevate to 85° and has on mount AA shell fuze setters.
 The 38 caliber barrel was a mid-length compromise between the previous United States standard 5"/51 low-angle gun and 5"/25 anti-aircraft gun.
 United States naval gun terminology indicates the gun fired a projectile 5 in in diameter, and the barrel was 38 calibers long, making the 5"/38 dual purpose midway in barrel length between the 5"/51 surface-to-surface and the 5"/25 anti-aircraft guns.
 The increased barrel length provided greatly improved performance in both anti-aircraft and anti-surface roles compared to the 5"/25 gun.
 However, except for the barrel length and the use of semi-fixed ammunition, the 5"/38 gun was derived from the 5"/25 gun.
 Both weapons had power ramming, which enabled rapid fire at high angles against aircraft.
 The 5"/38 entered service on USS "Farragut" , commissioned in 1934.
 The base ring mount, which improved the effective rate of fire, entered service on USS "Gridley" , commissioned in 1937.
Minas Geraes, spelled Minas Gerais in some sources, was a dreadnought battleship of the Brazilian Navy.
 Named in honor of the state of Minas Gerais, the ship was laid down in April 1907 as the lead ship of its class, making the country the third to have a dreadnought under construction and igniting a naval arms race between Brazil, Argentina, and Chile.
The BL 14 inch Mk VII naval gun was a breech loading (BL) gun designed for the battleships of the Royal Navy in the late 1930s.
 This gun armed the "King George V"-class battleships during the Second World War.
The "Rivadavia" class consisted of two battleships designed by the American Fore River Shipbuilding Company for the Argentine Navy.
 Named "Rivadavia" and "Moreno" after important figures in Argentine history, they were Argentina's entry in the South American dreadnought race and a counter to Brazil's two "Minas Geraes"-class battleship s.
Type 3 120 mm 45 caliber naval gun was a Japanese naval gun and coast defense gun used on destroyers, submarines and torpedo boats of the Imperial Japanese Navy during World War I and World War II.
 The proper title of the gun under the Japanese naval artillery naming system is 12 cm/45 3rd Year Type naval gun.
 Other guns using this naming system are the 41 cm/45 3rd Year Type naval gun, 20 cm/50 3rd Year Type naval gun, 15.5 cm/60 3rd Year Type naval gun and the 12.7 cm/50 Type 3 naval gun.