This tactic is illustrated in the 2009 battle of COP Keating, where the outpost was overrun, and eight soldiers and four Afghan allies were killed by Taliban fighters attacking from the high, steep mountainsides surrounding the base. The enemy recognized that the Americans’ best means of fighting back (at least until air support could come on station) was with their longer ranged .50 caliber M2A machine guns. The attackers massed fire on the emplaced guns and gun trucks, taking them out of the fight in the early stages of their attack.
FILLING THE GAP
By 2016, the problematic capability gap between America’s medium and heavy machine guns was well defined and the solution was identified in the form of the 338 Norma Magnum (338 NM) caliber cartridge. The 338 NM cartridge provides triple the ballistic performance of a 7.62 NATO cartridge fired from an M240B. Its performance is closer to that of the 50 BMG, but at less than half the weight and size of the .50 cal. round, and when carrying a machine gun, weight is paramount.
In 2017, with the procurement process only in the ideation phase, SOCOM hosted an industry day and invited interested vendors to submit their ideas and designs for a lightweight medium machine gun (SOCOM used the nomenclature “LWMMG” at the time). Instead of stating hard requirements for the vendors’ systems to meet, SOCOM offered general performance goals and capabilities in an effort to give industry wide latitude in its response. However, SOCOM did have a few sticking points that were non-negotiable including weight, dimensions, and caliber, which provided the vendors a hint of the weapon it thought would fit its needs. What they were asking for was a sub-24-pound, belt-fed, 338 NM-chambered machine gun with suppressed and unsuppressed, quick-change, 24-inch barrels, a rate of fire from 500 to 600 rounds per minute (RPM), and an area target range of 2,000 meters.
The challenge piqued the interest of the SIG SAUER defense team and engineers, and thus the SIG Machine Gun program came into existence; the program, in its infancy, was founded with the mission to fill the U.S. machine gun capability gap with a SIG-designed and built machine gun chambered in 338 NM. Ron Cohen, CEO, had always envisioned that SIG SAUER would evolve to become the premier provider of small arms to the U.S. military with the crown jewel of that suite of weapons being a machine gun. This was that opportunity.
The company assessed its capabilities, marshaled its forces, and assembled a dedicated machine gun design team that would eventually number 25 members within its engineering efforts and Special Weapons Group (SWG).
START LIGHT
Between 2017 and 2018, SIG developed its very first machine gun, a lightweight medium machine gun prototype it called the SIG-Medium Machine Gun 338 (SIG-MMG 338).
The traditional approach in building a lightweight machine gun is to build a reliably working prototype, then shave weight wherever possible in ways that the gun is still able to meet its performance and reliability objectives. The challenge with this approach is that the lightest version of the gun remains elusive, as engineers, by practice, tend to be cautious and will leave meat on the bone for fear of compromising reliability.