The firing of heavy machine guns from the Spanish NH-90 helicopters of the FAMET

The NH-90 transport helicopters used by the Spanish Armed Forces are assigned various tasks.

The accident of an NH-90 Sarrio helicopter of the Spanish Army on a night flight
Airbus shows the three Spanish versions of the NH90 military helicopter together at last

The NH-90 Sarrio of the Third Maneuver Helicopter Battalion (BHELMA III) of the Spanish Army Airmobile Forces (FAMET), based in Agoncillo (La Rioja), have tactical transport as their main mission, but they can also carry out close air support missions thanks to their FN M3M heavy machine guns, caliber 12.7 mm. The Army has published a video today showing a shooting exercise with these machine guns:

#Buenosdías ¡No te pierdas este impresionante vídeo📹! Tiradores de Helicópteros #NH90 del Batallón de Helicópteros de Maniobra III de las #FAMET, realizan ejercicios de tiro 🎯como parte de la instrucción de sus tripulaciones, tanto en arco diurno como nocturno.
¡Descubre la… pic.twitter.com/BWW0iN530C

— Ejército de Tierra 🇪🇸 (@EjercitoTierra) March 4, 2025

The FN M3M heavy machine gun is a variant of the famous Browning M2. The M3 was developed during World War II for use on aircraft. In the US Armed Forces, the M3M is known as the GAU-21/A, which is its most widely used designation. It was designed for the US Navy in 2004.

While a Browning M2HB (a widely used variant of the M2 today) has a rate of fire of between 450 and 550 rounds per minute, an M3M can reach a rate of fire of 1,100 rounds per minute. Both the M2 and M3M have an effective range of about 2,000 meters, and can reach up to 6,800 meters.

The M3M's high rate of fire generates more heat in the barrel, which is why this machine gun features a perforated sleeve around its barrel to improve cooling and extend its lifespan. Each barrel of an M3M can withstand up to 10,000 rounds, according to the manufacturer. In addition, the M3M features a flash suppressor on the end of its barrel, in order to reduce its firing signature and improve its compatibility with night vision equipment.

In this image we see the gunner wearing a Gentex HGU-56/P helmet with maxillofacial protector, commonly used by FAMET helicopter crews. As we can see in the video, the M3Ms mounted on the Spanish NH-90s carry DI Optical DCL120 red dot sights. This sight is a model specially developed for 12.7 mm calibre heavy machine guns. These sights weigh 3,100 grams and allow the gunner to improve their aim both day and night. They can operate in extreme conditions, from 71ºC to -41ºC.

Finally, in the video we see the replacement of the ammunition box that feeds the M3M machine gun. If I'm not mistaken, what we see in this case is a box of 200 cartridges.