The Army is Developing a New Bullet: Here's What We Know

The United States Army is in the process of developing a new round that will replaced the 5.56mm NATO in use for most soldiers. In doing so, they’re also asking for new rifles and machine guns to replace the M4 and the M249.

This represents a fairly dramatic shakeup in modern infantry combat, and there will be interesting developments that come from this. Here, I’m going to give you the highlights of the story so far, and some of my thoughts on where it might be heading next. These are interesting times in firearms design to be sure.

The M16, firing 5.56mm NATO, is in its sixth decade of service with the US Army: that makes it the longest-serving rifle in modern military history without a re-chambering. Sure, a modern M4 might not look much like a Vietnam-Era M16A1, but the same operating system and bullet have been around, and in effective use, for long enough that three full generations have put it to use. It’s pretty clear, then, that the Army is attached to their M16, and for good reason: it has proven to be a light and reliable weapons system in a wide variety of conflicts.

Coming out of the barrel of the M16 is the 5.56mm NATO. I bring up NATO here since it has not only been adopted by the US, but nearly all of our allies as well. This was the entire point of the round’s development: if NATO ever did go head to head with the Soviet Union, the leadership of NATO wanted the countries to share as many supply lines as possible, and sharing a bullet in common for rifles and machine guns was a major part of that, and it still is today. Many countries use the M16, and many of those who don’t use weapons that take AR magazines.

As well-loved as the 5.56mm is, it has, in recent years, shown some limitations. Because it is a light bullet, the 5.56mm does not do well against hard cover, or at extended ranges. It might not be the best rifle to take into long-range firefights in mountains where there are a lot of rocks for cover. This, incidentally, is a good description of the fighting that has taken place in Afghanistan for the last two decades. In response to this, several services went to new weapons, like the SCAR, or old ones, such as the M14, in a larger caliber, to get the job done. But that was a stopgap solution, and now the Army is in the process of developing a new bullet, the 6.8 New Generation Squad Weapon, or NGSW.

In addition to being a larger projectile, 6.8mm over 5.56mm, the 6.8NGSW has one feature that makes it stand out in a display: it’s caseless. Well, sort of. Instead of a standard brass case like most bullets have had for the last century, the 6.8NGSW has a polymer case that takes advantage of new materials. This gives the bullet a more squared-off look and necessitates the development of a new set of guns out of which it is to be shot.

One of the biggest benefits of the polymer case is the weight. Even with a larger projectile, the 6.8NGSW is about a third lighter than the 5.56MM. If anything will lead to soldiers liking the round, I would bet on it being this. If you keep the combat loadout the same in terms of rounds, it means a lot less weight banging on your back and knees all day. But, if you need to go into a firefight well prepared, the ability to carry a lot more rounds for the same weight will be much appreciated by those who expect heavy combat. Given the sheer weight of gear that folks often carry into battle now, this is a game-changer.

Sig Sauer is having a great couple of years. Recently, their M17 has become the new standard-issue pistol of the Army, and now they’re throwing their hat into this ring as well, developing what they call the NGSR and the NGSWAR, a series of rifles of machine guns means for this new round. Both of these take design cues from the existing M4 and M249 and will look familiar to those who like Sig’s products. Effectively, these look to be modernized versions of proven platforms and in form factors that will make updating training easy for most units.

Taking things in a new direction, General Dynamics’ entry into the program, which they’re calling the RM277, is a bullpup. That means that the magazine and operating parts of the rifle are behind the trigger, which is the reverse of the M16. The result is a much shorter rifle for the same barrel length, which some folks quite like. While the idea might take some getting used to for M16 fans, other countries have learned to love their bullpups in NATO; the UK, Germany, and France have all produced and fielded bullpups in the last few decades. Training might be a little trickier, but the more compact nature of bullpups might win over even some of the harsher critics.

What does all of this mean for NATO? It might lead to a situation in which more countries adopt the round, but likely only after some bickering. It’s happened before: when most countries in the alliance developed around a .303 British cartridge, the US, on our own, decided that, no, the .308 was going in our M14. This lead, eventually, other countries to follow along, at just about the time we ditched the .308 for 5.56mm. Arms standardization in NATO has always been tricky, and it looks like we’re going to enter in a new phase of figuring out tough logistics.

To recap: the m16 and the 5.56mm are fantastic as a combination of rifle and round, but are showing their age since it was first fielded in 1964. The Army is looking to replace that older round with the new 6.8NGSW, which will be a polymer-cased bullet that saves weight and increases range. To fire it, a few companies are developing rifles in several formats. While this is certainly interesting, it does raise questions about the future of not only the US army, but NATO as a whole, meaning that this is a story that will likely continue to develop for years to come.