The US is revolutionizing the caliber of infantry weapons

(To Tiziano Ciocchetti)

Recent operational theaters, such as Afghanistan, Iraq and Syria, have highlighted how Western forces were experiencing difficulties in gunfights against groups of jihadist militiamen armed with assault rifles / LMGs formerly Soviet AK47 / AKM, RPD in caliber 7,62x39 mm and 7,62x54 mm.

The coalition platforms (M-16A4 / M-4A1, C-7/8, SC-70/90, SA-80, FN-MINIMI / M-249 SAW), all in caliber 5,56x45 mm, did not reach ballistic performance of the aforementioned weapons, hence the need for the US Army to launch a program for a new assault rifle and a new team weapon.

Officially launched in 2018, as an extension of the NGSAR (New Generation Squad Automatic Rifle) program, the new program is divided into two parts: NGSW-R (New Generation Squad Weapon-Rifle) and NGSW-AR (New Generation Squad Weapon-Automatic Rifle ), and is intended to replace the M-249 SAW and the M-16 / M-4A1 series.

Among the three finalist companies, there is also SIG Sauer (which three years ago won the tender for the new US Army pistol with the P-320 model), which recently at the SOFIC (Special Operations Forces Industry Conference) in Tampa , has submitted both of its proposals to meet US Army requirements.

As for the need for a new assault rifle, the Swiss-German company has created a modified version of the MCX-MR (Medium Range) in size 6,8x51 mm (with a 20-round tank capacity) - originally configured in 7,62x51 mm for the CSASS (Compact Semi Auto Sniper System) program, later won by Heckler & Koch with the G-28 - equipped with an extensible polymer stock; the operating system uses a long stroke gas piston.

Inside the face of the shutter we find two punch ejectors; externally, the presence of two cocking levers is highlighted: the classic T on the M-4 model, ambidextrous and positioned on the upper part, plus one placed laterally and foldable. As for the release commands of the box magazine we find a lever on both sides of the weapon.

While for the LMG (Light Machine Gun) version, the SIG Sauer offers a compact machine gun (always in the 6,8x51 mm caliber) equipped with a telescopic polymer stock (and folding, on the ARX model), with an aluminum barrel and equipped with a short feeding door. The direction of feeding of the belt would be reversible by the operator, the cocking lever is positioned on the right side.

The cartridge ejection window is located at the bottom on the right side of the weapon. The fire selector has three positions: safe, semi-automatic and free burst. The Sig machine gun adopts a gas subtraction system, with partially recoil barrel, in order to better manage the recoil during the burst shot.

The common denominator of the three competing projects is the new 6,8x51 mm caliber. SIG Sauer developed the 6,8 Hybrid (photo), a bi-metallic hybrid cartridge (brass case and steel case back).

The weapons of the SIG are certainly more conventional than those presented by the other two competitors, especially compared to the RM-277 (v.articolo) of the GD / BDT (in bullpup configuration), however they are based on platforms already tested and appreciated by various western special forces.

Photo: US DoD / SIG Sauer