February 8, 2025: Last year the U.S. Army began equipping troops with the new M7 6.8mm assault rifle and M250 6.8mm Light Machine-Gun or LMG. In 2023 the army placed the first mass production orders for the M7 and M250. These new weapons replace 1960s-era 5.56mm ammunition that also required a new generation of assault rifles and LMGs. The M-16/M-4 assault rifles and M248 LMGs will remain in service but the infantry and Special Operations Command or SOCOM troops will be equipped with the new 6.8mm weapons. SOCOM was responsible for the acceptance of the 6.8mm ammo and the new weapons and conducted the initial combat tests between 2001 and 2003.

The army received 17,000 M7s and 3,000 M250s in 2024. These were distributed to army troops initially. SOCOM has options because SOCOM has always been free to buy and use whatever weapons it believes it needs. That means SOCOM troops have several assault and automatic weapons available and the M7 is now part of the collection.

The current plan is to purchase enough of the 6.8mm weapons for all army combat troops. That’s about 60,000 shooters. The marines and SOCOM are also using the 6.8mm weapons, and that means about 30,000 more M7s are required. The army plans to eventually acquire 107,000 M7s for infantry and SOCOM, combat engineers and several other combat specialists.

Weapons manufacturer Remington began work on the new round in 2002. The new round used the case from the old Remington .30-.30 rimless round with a new 6.8mm bullet. SOCOM supported the 6.8mm round and began testing it in M-16s and M-4s modified to accommodate it. The 6.8mm round is more accurate at longer ranges and has more hitting power than the 5.56mm round the M-16 was originally designed for. Out to about 600 meters, the 6.8mm round has about the same impact as the heavier 7.62mm round used in sniper rifles and medium machine-guns. It took longer to get a new 6.8mm rifle and LMG designed and built. The new ammunition and weapons are the first new ammo and weapons developed for the American infantry in over 60 years. This continues a trend that began nearly a century ago.

During the 1930s, the Germans studied their World War I experience and concluded that a less powerful and lighter rifle round would be more effective. This resulted in research on a smaller 7mm round but, with World War II fast approaching, this effort eventually produced a shortened regular 7.92mm rifle round. During that war, the Germans developed the first modern assault rifle, the SG-44. This weapon looked a lot like the AK-47, and that was no accident. The SG-44, like the AK-47, used a shortened rifle cartridge that was developed before the war. This was the 7.92mm for the Germans and 7.62mm for the Russians, which is still used in the AK-47. This gave the infantryman an automatic weapon that could still fire fairly accurate shots at targets 100-200 meters away. The SG-44 and AK-47 rounds had about the same stopping power as the new 6.8mm at those shorter ranges.

The AK-47 didn't have the accuracy of higher powered bullets, but the Russians didn't see this as a problem because most troops using it had little marksmanship training. If they had to kill someone, they could fire at full auto. The U.S. M-16 and its high speed 5.56mm round were more accurate than the AK-47 when firing individual shots at shorter ranges. But the wounding power of the 5.56mm bullet fell off rapidly at ranges over a hundred meters. The American military, and especially SOCOM, train their troops to fire individual shots, and do it with great accuracy at any range. A number of new rifle sights have made it even easier to do and makes first round hits at longer ranges easier to make. This made the shortcomings of the 5.56mm round at longer range more obvious.

SOCOM tested the 6.8mm round in Iraq and Afghanistan and the users liked it. But there was resistance from senior non-SOCOM generals to proposals that the 5.56mm round be replaced with the 6.8mm. To further complicate matters, there was a new 6.5mm Grendel round being tested as well, and some troops preferred it to the 6.8mm. This was because the 6.5mm round was more accurate than the 6.8mm one at ranges beyond 500 meters. The 6.8mm round won that dispute as well. In part this was because the 6.8mm round was more effective against the body armor enemy forces, including irregulars, are increasingly using.

The M7 weighs 3.8 kg. Add the optional sound suppressor and that’s 4.46 kg. The heaviest 5.56mm rifle is about 4 kg but most 5.56mm rifles weigh a little less than the M7. When fitted with a suppressor the M7 is 914mm long. The barrel itself is 330mm long. The larger and heavier 6.8mm round means the 30-round magazine is no longer used. Instead, a 20 or 25-round magazine is available.