If you asked me what an ideal sniper rifle looked like before 9/11, I would have described a super-accurate custom bolt-action rifle chambered in .300 Winchester Magnum.

After several combat deployments, including more than one as a sniper, I now think of a far different weapon: one that is lightweight, capable of sustained semi-automatic fire and has sufficient accuracy to take out targets at up to 500-800 meters. Those rifles are known in the Naval Special Warfare community as the MK11 Model 0 SWS (Sniper Weapon System) and the MK12 Mark 0/1 SPR (Special Purpose Rifle), two weapons that hold a special place in my heart.

In the summer of 2004 I led a SEAL sniper element into war-torn Najaf, a stronghold for Shiite cleric Muqtada al-Sadr and his Mahdi Militia. Our mission, as written by Dick Camp in his authoritative account of the battle in his book Battle for the City of the Dead was to “(1) kill Mahdi Militia fighters, (2) deny the enemy the ability to place effective fire on friendly forces, and (3) attrite enemy forces.” It was a special operator’s dream. We were working with the Army’s 2-7 Cavalry and 1-5 Cavalry, taking back the city building by building, street by street. Having access to Bradley Fighting Vehicles, Abrams tanks, and up-armored HMMWVs allowed us to bring our entire arsenal of sniper weapons into the city.  We started taking long shots with our .50s but, as we pushed into the city, we did a lot of work with our bolt-action .300s. When we really got into the fight and were clearing buildings and then using them as overwatch positions, we went to the auto loading 7.62 Mk11s.  We kept the bolt action weapons with us for specific targets but the workhorse became the Mk11s due to the intensity of the fight and the sheer number of enemy forces.

The Mk11 Mod 0 is the Navy’s designation for the Knight’s Armament Company (KAC) SR-25, a 7.62x51mm semi-automatic rifle based on Eugene Stoner’s AR-10 design. Mr. Stoner and C. Reed Knight Jr. worked collaboratively on this and other projects in the 1990s since Stoner lived in close proximity to KAC’s Vero Beach, Florida headquarters. Interesting that, even four decades after his initial design changed military hardware forever, Stoner was still on the cutting edge of weapons design. My co-author, Keith Wood, was fortunate enough to visit Stoner’s home as a teenager and vividly remembers being shown a design drawing of an early SR-25, complete with a prototype of what would become the modern-day rail system, by the master himself. 20 years later, I would use the Mk11 rifle in combat. Interesting how the world works…

Our Mk11s were equipped with Leupold Mk4 3.5-10x40mm scopes with a MIL-DOT reticle though these were eventually replaced with Nightforce optics due to their reliability and ruggedness. Nightforce rings were used, even with the Leupolds, and an ATPIAL IR laser was attached to the rifle’s railed forend. Our rifles were almost always used in conjunction with a KAC Mk 11-0 suppressor (big and heavy but effective) fixed to the rifle using a vertical pin that slid into a notch milled into the gas block. Our rifles came equipped with 20” match barrels made by Obermeyer and we used M118/M118LR ammunition. Weapons and optics have seen unprecedented innovation in the past fifteen years but, at the time, the Mk11 was cutting edge technology.

Despite being a semi-automatic, the Mk11 was sufficiently accurate for our purposes and, because it was a semi-automatic, was capable of taking out multiple targets in rapid-succession or taking quick follow-up shots as required. Its sound and flash signature was minimal, thanks to the suppressor, which made our firing positions more difficult to locate. One of the best things about this system though was that, instead of taking an assault rifle and a sniper rifle on a mission, we could head outside the wire armed with just a Mk11. When you’re carrying all of your weapons and gear in temperatures well-north of 100 degrees under your own power, this is an important consideration.

As great an asset as the Mk11 was, it was still big and heavy. When the mission didn’t require the greater reach of the 7.62mm cartridge, we carried an even more portable weapon, the Mk12 Mod 0/1 SPR. The 5.56x45mm Mk 12 was built by Naval Surface Warfare Center Crane Division and filled an important niche in-between the M4 and the Mk11. This weapons system was only slightly larger and heavier than the M4, but could be used effectively as a sniper rifle at ranges out to 500 or more meters. Though our Mk12s were issued as complete rifles with two-stage match triggers, the uppers were interchangeable with standard M4 lowers. I used a fixed M16-style stock on my Mk11 but some users opted for various other stocks, including the SOPMOD collapsible unit.

Mk12s use an 18” free-floating barrel with a fairly heavy profile and a rifle-length gas system which was long enough to give us the velocity we needed for longer shots but short enough to be relatively compact.  Our Mk11s all used KAC rail systems to which we mounted bipods, ATPIAL IR lasers and Surefire Scout lights.  The Ops, Inc. 12th Model suppressors threaded onto the Mk12’s distinctive muzzle brake and centered onto a ramped locating collar that was attached to the barrel. 

When it came to optics, our Mk12s were equipped with the 2.5-10x24mm Nightforce NXS Compact, one of my all-time favorite riflescopes.  I mounted a J-Point red dot at the 1:30 position in case I had to use the rifle at close quarters.  This gave me the best of both worlds.  We used ARMS quick detach throwlever scope mounts in case we needed to ditch the scope and use the backup iron sights; something that, fortunately, I never had to do.  With Mk262 MOD 1 77 grain ammunition from Black Hills, these rifles were extremely accurate and effective. 

In places like Najaf and Ramadi, we would find ourselves clearing rooms and then engaging the enemy at long range just moments later.  Like the 7.62mm Mk11, the Mk12 could be used in both roles. The Mk12’s lighter weight and more compact length made it extremely versatile.  One or the other was never out of arms reach after leaving the wire.

These two weapons fill overlapping niches in modern combat, particularly in urban or built-up areas.  More advanced weapons systems are coming on-line today but, when I was in the fight, we felt extremely fortunate to have the Mk11 and Mk12 in the arsenal. 

For more reading on this topic, I highly-recommend the Vickers Guide AR-15 Volume 2 by my friend Larry Vickers and, if you’re interested in owning a Mk12 clone, my old teammate Monty LeClair at Centurion Arms is the man to call.