Smaller in both size and budget, the Marine Corps often lags behind the Army when it comes to infantry rifles. Early in World War II, Marines were still using bolt-action M1903s from the previous World War, while the Army fielded the semi-automatic M1 Garand. During Operation Iraqi Freedom, Marines cleared houses with old M16s sporting 20-inch barrels, while soldiers collapsed the stocks of their handier M4 carbines. This time, however, will be different. When it comes to the Army’s adoption of the M7 rifle, the Marine Corps has decided not to follow suit.Also Read: Flintlock to Firepower: The grunt’s 250-year quest for a weapon that actually worksFirst contracted in 2022 under the Next Generation Squad Weapon Program, the M7 rifle fires the new 6.8x51mm cartridge. Designed to defeat modern armored threats, the rifle is also equipped with an advanced electronic optic and suppressor. But all of these enablers add weight. Moreover, the larger, heavier cartridge means troops carry less ammo. Ironically, these and other issues were presented to the Marine Corps by an Army officer. Captain Braden Trent briefed his report on the rifle at the 2025 Modern Day Marine exhibition in Washington, D.C. In addition to weight and reduced ammunition capacity, Trent noted unusually high wear on barrels, bolts, and suppressors. Echoing Trent’s concerns, the Director, Operational Test and Evaluation, published an FY24 report stating, “The XM7 with mounted XM157 demonstrated a low probability of completing one 72-hour wartime mission without incurring a critical failure.” One of the chief complaints about the M7 is that it weighs more than the M14. (U.S. Army) With all of this, the Marines said, “Thanks, but no thanks.”“The Marine Corps will retain the M27 for our close combat formations as it best aligns with our unique service requirements, amphibious doctrinal employment of weapons, and distinct modernization priorities, while ensuring seamless interoperability across the Joint force and with coalition partners,” a Marine Corps spokesperson confirmed to Task & Purpose via email. “We will continue to monitor development of the M7 [Next Generation Squad Weapon rifle] to inform future requirements.”Originally adopted in 2011 to replace the M249 Squad Automatic Weapon, the M27 is designated as an Infantry Automatic Rifle. Based on the legendary Heckler & Koch HK416, the M27 eventually replaced the M4 carbine in Marine Corps infantry units. The HK416 also serves as a standard service rifle for the armies of Norway, France, Germany, and Luxembourg… all NATO members. The M27 can also be configured with a short barrel for reduced size and weight. (U.S. Marine Corps) Critically, the M27 fires the NATO standard 5.56x45mm cartridge and feeds from STANAG magazines. As the Marine Corps spokesperson pointed out, this enables interoperability with foreign partners. If a Marine Corps unit runs out of ammo for their M27s, they can be resupplied from any NATO ally’s stockpile. Army units armed with M7s are restricted to their own supply chains and can’t share their 6.8x51mm ammo with anyone else.Historically, this isn’t anything new. The United States forced the rest of NATO to adopt 7.62x51mm, reneged on its part of the deal, and ended up adopting 5.56 anyway. So, while the Army plays to its own tune, at least the Marine Corps is keeping in line with the alliance. Don’t Miss the Best of We Are The Mighty • The infantry hates the XM7 rifle (and why the Army doesn’t care)• Here are the major lessons I learned from carrying the M27• What troops really think of the Army’s new XM7 rifle Weapons Weapons Marines reject Army’s SIG M7 rifle, opting to keep H&K M27 By Miguel Ortiz Movies You could be the next owner of Darth Vader’s revolver By Miguel Ortiz Weapons The legendary HK416 rifle’s biggest competitors might be its own descendants By Miguel Ortiz Feature The Swedish sledgehammer: A salute to the Carl Gustaf, long may the ‘Goose’ reign By Adam Gramegna Feature Ukraine turned war into a point-based game with a real-world rewards market By Adam Gramegna The post Marines reject Army’s SIG M7 rifle, opting to keep H&K M27 appeared first on We Are The Mighty.