By: Justin Hilbert

The United States Marine Corps is upgrading its scout sniper rifle to the Mk 13 Mod 7 .300 Winchester Magnum, ending its run with the M40 after 50 years.

The 7.62×51 Remington 700 bolt-action was the basis for the M40 series – the Corps’ choice since 1966. The antiquated rifle system has gone through various evolutions to increase durability and performance and to decrease weight. But even the current M40A6 configuration was found wanting in the modern warfare scenarios of Iraq and Afghanistan.

The M40A6 sniper rifle system is accurate out to 1,000 yards, but only really effective up to 875. The rifle’s ineffectiveness in successfully engaging adversaries downrange has reportedly been a matter of frustration for Marine scout snipers. Meanwhile, the Army’s designated marksmen have been equipped with the M2010 Enhanced Sniper Rifle, which is effective at ranges upwards of 1,300 yards, and SOCOM’s (Special Operations Command) Precision Sniper Rifle, which hits targets effectively at 1,600 yards.

The Mk 13 Mod 7 .300 Winchester Magnum rounds will increase the Marine scout snipers’ effective range to the coveted 1,300-yard range the Army and Special Forces have been hitting for years. Tacking on a few football fields’ worth of distance is a big deal. Chris Kyle brought a lot of attention to the Mk13 .300 Win Mag by stating it was his preferred rifle for most engagements.

What Does the Mk 13 Mean for Soldiers on the Ground?
I asked a friend of mine who is a former Marine well-versed in the M40 who worked as a security contractor in Afghanistan about the differences between the two rifles, and what they will mean for all Marines, not just snipers.

“[The Mk 13] is what the SEALs always used. Simply put, the .300 Win Mag has better ballistics and can find its target and touch someone with enough kinetic energy after 1,000-yards to still put them down.

“With the M40, you could see [the enemy], but the 7.62 & .308 rounds don’t carry enough kinetic energy to knock them down at 1,000 yards and beyond. That’s a frustrating problem that is finally getting resolved. And as far as the mods go on the new rifle system … lighter, faster, and more durable is always a huge win for the guys on the ground.

“Again, the ballistic coefficient with the .300 is just better. You have a lot fewer adjustments to account for as it bucks the wind. The 7.62 round drops faster and is affected by the wind more. When long-range shots are needed, the more help you can get the better. Scout snipers will now be more effective in engaging at distance and keeping the rest of their units safe.”

What Took So Long?
I also asked my friend his thoughts on why it took the Corps so long to upgrade their Sniper Rifle System when other branches of service issued their soldiers arguably superior rifle systems years ago. He told me the Marine Corps loves tradition. The M40 had become a tradition, and even though it wasn’t necessarily the best tool for the job anymore, it would take a lot to move away from that rifle, because the M40 has been the Scout sniper rifle since Vietnam.

But military officials have been hearing the same complaint form warfighters for so long, it apparently become too frequent to ignore. And it’s finally been acknowledged that a maximum range of 1,000 yards is no longer viable for the military engagements of today.

“How and when the service plans on fielding its new suite of precision weapons, like every other new piece of gear in the U.S. armed forces, remains to be seen,” wrote Jared Keller, senior editor at Task & Purpose. “But no matter when it reaches Marine scout snipers, the new rifle represents a major, long-awaited breakthrough for the Corps — and certain doom for their adversaries downrange.”

Who Is Fulfilling the Mod 7 contract?
There’s not much public information available on the Mk 13 contract. I reached out to Arsenal Democracy, who builds a fantastic Mk13, to see if I could learn more, and they pointed me in the right direction. The Marine Corp’s new Mk 13 Mod 7s are being assembled and distributed by NAVSEA Crane (Naval Surface Warfare Centers, in Crane, Indiana) Expeditionary Warfare division.

Both the AD Mk13 and the Marines’ new Mod 7s use the Accuracy International PSR chassis (AICS long-action stock), but the Mod 7 utilizes the Stiller Mk13 action and a 26”, 4-groove Lilja barrel with 1:10 right-and-twist.

Justin Hilbert is a copywriter and content strategist, writing from Florida and Costa Rica. Contact him at

Photo Credit: Creative Commons