The Mexican military-industrial complex likes to keep things homemade: the army’s principal rifle, which comes in both assault and carbine form, is produced by the army for the army.

In a factory in Naucalpan de Juárez, México state, 402 soldiers are in charge of the construction and assembly of almost all of the weapon’s 112 components, and the production of up to 30,000 units a year.

When it began to be made in 2005, the FX05 Xiuhcóatl rifle — taking its name from the Náhuatl word for “fire serpent” — replaced the German-made G3 rifle.

The Xiuhcóatl has a rate of fire of 700 to 800 rounds per minute. Its effective range is 200 to 800 meters with the use of sight marks, and it has mechanical, telescopic and red-dot sights, according to Iraq veteran and blogger Allan Wall writing on Banderas News in 2007.

Colonel Rafael Correa, the factory’s director, explained how the rifle took prominence.

“In 2005, a group of fellow military engineers carried out the research …. before they designed and managed to manufacture the FX05 snake Xiuhcóatl rifle … This rifle was put to the test for several years in mud and in water in order for it to work correctly and to be sure of its correct operation — and that its design would allow the soldier to be safe in his different operations,” he said.

“For the design of this rifle, the military engineers who developed it took into consideration all the ergonomics of the Mexican soldier … It allows the soldier better accommodation for when he performs his duties,” Correa added.

Wall wrote that the weapon was well-suited to combat in urban areas: “Switching from the G-3 rifle to the FX-05 means that the Mexican army is changing from a 7.62 mm to a 5.56 mm round for its main assault rifle. The 7.62 mm round is right for an open battlefield situation, while the 5.56 mm is more suitable to close-quarters urban combat, plus it weighs less, so more rounds can be carried,” he wrote.

The production of the Xiuhcóatl was at one point, however, at the center of controversy, when Mexico switched away from the G3 in 2005.

“The German government and [G3 manufacturer] Heckler and Koch (HK) have accused Mexico of copying the G36V design for the FX-05 [Xiuhcóatl]. In fact, they threatened to take the case to international tribunals, and demanded that Mexico destroy the FX-05 and pay damages to HK,” Wall said. “As a result of the German threat, in November of 2006, Mexico stopped manufacturing the new rifles,” he said.

However, he added that HK representatives dropped the dispute after an “inspection and exhibition of the weaponry” in 2007.

The factory in Naucalpan de Juárez has production planned until 2023, when it will move to the Oriental military camp in Puebla as part of the government’s plan to modernize Mexico’s military industry.

With reports from Milenio