The news of SIG winning the 6.8mm NGSW competition rightly captured the attention of the industry and gun enthusiasts everywhere….and for good reason. It is not everyday that the US Army selects a new caliber, a new infantry rifle AND a new belt-fed machine gun all at the same time. After all, the 5.56mm and 7.62mm NATO cartridges have dominated the world of small arms for over sixty years.
After standardization of the 7.62x51mm NATO cartridge in 1954, both the US and Europe moved quickly to adopt rifles and belt-fed machine guns based on the new ammunition. The FN FAL Rifle and the US manufactured M-14 rifle were adopted in the late 1950s and the FN MAG belt fed machine gun and the US M-60 machine gun also came into service around the same time. The smaller, high-velocity 5.56x45mm began making inroads in the mid-1960s with the US designed M-16 rifle in Vietnam. By the end of that decade, the new lightweight M-16 had started to replace the heavier M-14 as the front-line rifle for US forces. European NATO countries took longer to adopt the 5.56, but by the end of the 20th century, it was quickly becoming the caliber of choice for most infantry rifles fielded by Western armies.
So, for six decades, US and European small arms came in basically two chamberings: 5.56 or 7.62. As a result, the introduction of SIG’s new 6.8x51mm hybrid (brass and steel) cartridge, operating at chamber pressures of 80,000 PSI, is in fact a big deal. Muzzle velocity of 3000 feet per second (914.4 meters per second) from a 16” (406.4mm) barrel is impressive. No one should underestimate the significance of this new cartridge that has now been “blessed” by the most powerful--- and the most professional--army on earth. The 6.8x51mm cartridge has only one way to go….and that is up.
The fact that SIG won this competition was hardly a surprise to most industry observers. Since joining SIG almost 20 years ago, CEO Ron Cohen has done a remarkable job in turning the company around. Not only did he reverse the fortunes of their moribund pistol line but his entry into the AR-15 rifle market re-energized the company and returned it to solid financial footing. Mr. Cohen took advantage of the enhanced profitability to focus on government and military contracts and establish the company as a serious player in the defense industry, taking on giants like Beretta and Glock and making significant inroads against both. The SIG 320 pistol beat both Beretta and Glock--- and entrants from FN, Smith and Wesson and CZ--- in the competition for a new 9mm XM17 modular handgun.
One of the key considerations in awarding any government contract is the ability of the bidders to be able to successfully manufacture and bring to market the product. In this regard, SIG was the obvious choice. Not only do they have a state-of-the-art US manufacturing facility, but they have over 2000 skilled workers and a proven track record of performing well on other Army contracts including the 9mm M17 and M18 pistols.
As a result, SIG is uniquely positioned to roll out these new weapons and their novel ammunition. Over a two-year period, the US Army worked hand in hand with SIG and other competing weapon designers in testing the new ammunition and firearms. An enormous amount of information was gained from these very in-depth technical and field trials. It is safe to say there will be few--- if any-- surprises as SIG now moves to full-scale production. The new XM5 rifle and XM250 weapons are the most thoroughly tested firearms in US small arms history. The same goes for the 6.8x51mm cartridge. The hybrid brass and steel cartridge design is unique, but it is still based on proven ammunition technology and is backwards compatible with large scale ammunition production facilities.
What is less certain is how quickly other countries will move to adopt the new cartridge or the new SIG weapons. Western armies have enormous stocks of both 5.56mm and 7.62mm ammunition and weapons. They are far from obsolete and for many countries, these existing calibers perform just fine. Part of the reason for the new 6.8x51mm cartridge was to provide enhanced performance against near-peer adversaries using body armor. Not every military is facing that threat and, as a result, they will be hesitant to switch over.
The 6.8x51mm is, however, easily interchangeable with many 7.62mm weapon systems, particularly machine guns with quick detachable barrels. Replacing the barrels on FN MAG or M240 7.62mm machine guns will be relatively easy for armies wishing to use the new 6.8x51mm. The 6.8mm has the same overall length as 7.62 NATO, and it has the same .473-inch bolt face. The higher operating pressure may, however, shorten the lifespan of bolts and other weapon components designed around the lower pressure of the 7.62mm.
I am a fan of the new cartridge and the new weapons designed by SIG. Metallurgy has come a long way and SIG expects at least a 12,000-round barrel life with the higher chamber pressures. Still, I don’t think the new designs will replace the large stocks of existing rifles and machines guns anytime soon, including the US military’s own M4 carbine.
The US Army has indicated that fielding of the new weapons-- and their new cartridge--- will first go to front line combat units likely to engage with near-peer adversaries using body armor and requiring and weapons capable of engaging them from a greater distance. That is what the XM5 and the XM250 are designed to do, and they will do it very well. However, today’s 5.56mm rifles and 7.62mm machine guns and sniper rifles will be around for some time to come.
— Raul Mas
Mas is the editor of our Spanish language companion service The Outdoor Wire Espanol Edicion.