NATO's future? US selects new SIG Sauer XM5 6.8mm service rifle

The contract is done, the ink is drying, supposedly (although we've heard that one before). After years of research, testing and pontification from gun magazine editors, the US military has selected the SIG XM5 as its next-generation infantry rifle (aka NGSW, or Next Generation Service Weapon). The contract also includes a light machine gun based on this rifle; both firearms are chambered in the new SIG FURY 6.8 Common Cartridge Ammunition.

We discussed the US military's search for new service rifles in February, when we told you True Velocity's 6.8mm TVC composite-cased cartridge had gained SAAMI approval. Ultimately, SIG Sauer's cartridge and rifle design won this competition.

The SIG FURY 6.8x51mm cartridge had a hybrid steel/brass case that allows for pressures of 80,000 psi. It's based on a .308 design externally, necked-down to .277. Although it's a new design, remember that military firearms designers have been calling for a cartridge in this general range ever since the 1930s, with both British and American inventors saying this was the way forward. Were it not for the interruption of World War II, we might have seen a .270-class military cartridge decades ago.

As for the new service rifle, it is based on SIG's existing XMS rifle, with tweaks to handle the newer chambering. It's also redesigned to be transformed into the XM250 light machine gun configuration. Between these two firearms, frontline US Army and Marine Corps soldiers are expected to be re-armed over coming years, replacing the existing M4 carbine and M249 light machine gun. Support troops, and likely some National Guard (if history is any indication) will carry on with existing 5.56-chambered firearms, at least for now.

Both weapons come pre-set for use with SIG's SLX suppressor, which was part of the reason for the new cartridge chambering, indirectly. Military brass wanted a short-barreled rifle still capable of high velocity, which required the new high-pressure cartridge. The short barrel on the new weapons allows infantry to add a suppressor without making their rifle or LMG too long for practical use, particularly in urban areas.

So what's next? SIG Sauer is undoubtedly preparing to manufacture the new firearms in mass production, and no doubt some of the other companies involved in the bidding are also hoping for production contracts. Winchester is researching manufacturing plans for the ammunition itself. Within months (years, more likely), this new platform will be working its way into the hands of the US military.

But as for the rest of NATO? Given the miserly defence budgets of most of the involved countries, don't bet on a change-over anytime soon, at least not willingly. Maybe US pressure will convince other countries to switch over, but don't forget the US was willing to go it alone with 5.56 for many years before the rest of NATO got on board.