The .500 Nitro Express is a .510 caliber (13 mm) big bore hunting cartridge.
 It was designed for use in single shot and double rifles.
 The cartridge is available in two lengths: a 3.00 inch and a 3.25 inch version.
 The cartridge was designed for use against large dangerous game species in Africa and India.
The Sturmpistole (Assault-Pistol) was an attempt by Nazi Germany during World War II to create an anti-tank weapon which can be used by any infantryman.
 It consisted of a modified flare gun which would fire a variety of grenades, including a 0.25 ounce shaped charge warhead which could penetrate 80 mm of rolled homogenous armor.
 The idea was not pursued wholeheartedly due to its total ineffectiveness against even the lightest tankettes of its era, and took second stage to the then current anti-tank rifles and later weapon developments, such as the "Panzerfaust" and "Panzerschreck".
Anti-tank warfare arose as a result of the need to develop technology and tactics to destroy tanks during World War I.
 Since the first tanks were developed by the Triple Entente in 1916 but not operated in battle until 1917, the first anti-tank weapons were developed by the German Empire.
 The first developed anti-tank weapon was a scaled-up bolt-action rifle, the Mauser 1918 T-Gewehr that fired a 13mm cartridge with a solid bullet that could penetrate the thin armor of tanks of the time and destroy the engine or ricochet inside killing occupants.
 Because tanks represent an enemy's greatest force projection on land, anti-tank warfare has been incorporated into the doctrine of nearly every combat service since.
 Most predominant anti-tank weapons at the start of World War II were the tank-mounted gun, anti-tank guns and anti-tank grenades used by the infantry as well as ground-attack aircraft.
The 8×50mmR Lebel (8mm Lebel) (designated as the 8 × 51 R Lebel by the C.I.P.) rifle cartridge was the first smokeless powder cartridge to be made and adopted by any country.
 It was introduced by France in 1886.
 Formed by necking down the 11mm Gras black powder cartridge, the smokeless 8 mm Lebel cartridge started a revolution in military rifle ammunition.
 Standard 8mm Lebel military ammunition was also the first rifle ammunition to feature a spitzer boat tail bullet (Balle D), which was adopted in 1898.
 The long-range ballistic performance of the 8mm Lebel bullet itself was exceptional.
 For use in the magazine tube-fed early Lebel rifle, the 8mm case was designed to protect against accidental percussion inside the tube magazine by a circular groove around the primer cup which caught the tip of the following pointed bullet.
 However, the shape of its rimmed bottle-necked case, having been designed for the Lebel rifle's tube magazine, also precluded truly efficient vertical stacking inside a vertical magazine.
 The bolt thrust of the 8mm Lebel is relatively high compared to many other service rounds used in the early 20th century.
 Although it was once revolutionary, the 8mm Lebel was declared obsolete after World War I and was soon after replaced with the 7.5×54mm French round.
The Mauser 13 mm anti-tank rifle (, usually abbreviated T-Gewehr) was the world's first anti-tank rifle—the first rifle designed for the sole purpose of destroying armored targets—and the only anti-tank rifle to see service in World War I.
 Approximately 15,800 were produced.
The M18 recoilless rifle was a 57 mm shoulder fired anti-tank recoilless rifle used by the U.S. Army in World War II and the Korean War.
 Recoilless rifles are capable of firing artillery-type shells at reduced velocities comparable to those of standard cannon, but with greater accuracy than anti-tank weapons that used unguided rockets, and almost entirely without recoil.
 The M18 was a breech-loaded, single-shot, man-portable, crew-served weapon.
 It could be used in both anti-tank and anti-personnel roles.
 The weapon could be both shoulder fired or fired from a prone position.
 The T3 front grip doubled as an adjustable monopod and the two-piece padded T3 shoulder cradle could swing down and to the rear as a bipod for the gunner.
 The most stable firing position was from the tripod developed for the water-cooled Browning M1917 machine gun.
The Type I rifle "Arisaka" (イ式小銃 , "I-shiki shōjū" ) was produced during the early years of World War II for the Japanese Empire by the Kingdom of Italy ("Type I" is not a numeric symbol, it denominates "Italian").
 After the invasion of China, all Arisaka production was required for use of the Imperial Army, so under the terms of the Anti-Comintern Pact, the Imperial Navy contracted with Italy for this weapon in 1937.
 The Type I is based on the Type 38 rifle and utilizes a Carcano action, but retains the Arisaka/Mauser type 5-round box magazine.
 The Type I was utilized primarily by Japanese Imperial Naval Forces.
 It is chambered for the 6.5 x 50 mm cartridge.
 Approximately 80,000 Type I rifles were produced in 1938 and 1939, 40,000 manufactured by Beretta and an equal number by Italian government arsenals; the final shipment to Japan left Venice by submarine in 1941.
The vz.
 52 rifle (often incorrectly called the "CZ 52") is a self-loading rifle developed shortly after the Second World War in Czechoslovakia.
 Its full name is 7.62mm samonabíjecí puška vzor 52.
 Vz.
 52 is an abbreviation for "vzor 52", meaning "model 52".
 It fires the unique 7.62×45mm cartridge.
 It is considered both reliable and accurate.
 The first 5000 vz.
 52 rifles were made by Považské strojárne in Považská Bystrica, but due to production difficulties, its manufacture was taken over by Česká zbrojovka Uherský Brod.
The 7×57mm cartridge, also known as the 7mm Mauser, 7×57mm Mauser, 7mm Spanish Mauser in the USA and .275 Rigby in the United Kingdom is a first-generation smokeless powder rimless bottlenecked rifle cartridge.
 It was developed by Paul Mauser of the Mauser company in 1892 and adopted as a military cartridge by Spain in 1893.
 It was subsequently adopted by several other countries as the standard military cartridge.
 It is recognised as a milestone in modern cartridge design, and although now obsolete as a military cartridge, it remains in widespread international use as a sporting round.
 The 7×57mm has been described as "a ballistician's delight".
 Many sporting rifles in this calibre were made by British riflemakers, among whom John Rigby was prominent; and, catering for the British preference for calibres to be designated in inches, Rigby called this chambering the .275 bore after the measurement of a 7 mm rifle's bore across the lands.
An anti-tank rifle is a rifle designed to penetrate the armor of vehicles, particularly tanks.
 The usefulness of rifles for this purpose ran from the introduction of tanks in World War I until the Korean War.
 While medium and heavy tank armor became too thick to be penetrated by rigid projectiles from rifles that could be carried by a single soldier, anti-tank rifles continued to be used against other targets, though recoilless rifles and rocket-propelled grenades such as the bazooka were also introduced for infantry close-layer defense against tanks.
 Anti-materiel rifles of today, such as the Barrett M82, are a development of the Second World War technology.

Question: How many 13mm cartridge anti-tank rifles were produced for World War I?
Answer: 15,800