By now it is well known that the U.S. Army established a need to standardize a sniper rifle in 7.62x51mm NATO caliber. This was necessary in order to field one such rifle for precision sniping and to replace the literal myriad of sniper rifles currently in the system. For the record, these sniper rifles include the venerable M14 semi-automatic rifle and the M24 Remington bolt action rifle, the Mk 11 and others, which have been purchased by individual SOCOM units.
In the wake of 9/11 and America’s entry into the Global War On Terrorism (G-WOT), most of the remaining 40,000 M14 rifles in the U.S. military’s inventory (mostly the U.S. Navy) have been taken out of storage in order to be re-built as precision semi-automatic rifles for sniping use. Many of these rifles that weren’t destroyed during the Clinton Era were given to “friendly” countries and there has also begun a move to “buy” some of them back.
The M14’s popularity as a sniper rifle dates back to its development as a National Match competition rifle during the 1960’s, its evolution into the M21 Sniper Rifle used in the Vietnam War, and its evolution into the XM25 Sniper Rifle by the U.S. Army and Navy in the years that followed. Properly fitted, the M14 is capable of extremely good accuracy and is highly reliable, but it has had less than optimum results from being used with a sound suppressor. Still, the M14 has made the transition into a 21st Century Sniper Rifle as the DMR (Designated Marksman Rifle) by the United States Marine Corps and its more recent transformation by the U.S. Special Operations Command (USSOCOM).
Being a highly modified Model 700 Remington bolt-action repeating rifle, the M24 is capable of great precision accuracy. However, lessons were relearned in Somalia and in target-rich environments encountered in the G-WOT that a self-loading rifle can be fired in succession 4 to 5 times faster than a bolt action rifle. Thus, the Army was determined to standardize a semi-automatic sniper rifle.
The third rifle mentioned is the Mk 11, a refined version of the SR- 25 (Stoner Rifle-25) rifle, which is made by Knight’s Armament Company, of Titusville, Florida. Like the others, the Mk 11 is chambered for the 7.6x51mm NATO cartridge, but it contains modifications dictated by the U.S. Navy SEALS, which is a member of the SOCOM. However, using the Mk 11 identified issues that the Army found desirable in an AR10-style sniper rifle.
In an effort to obtain an optimum 7.62mm NATO Sniper Rifle, the Army issued a solicitation for a rifle to meet the specification of what it called the Semi-Automatic Sniper System (SASS). Note that, as opposed to the Mk 11 Sniper Rifle and others, the rifle meeting SASS requirements would not be produced in selective fire. Previously, some self-loading sniper rifles were looked upon as support weapons for the main sniper rifle, which was often a bolt-action repeater. While these self-loading support sniper rifles could be used alongside the repeating rifle, they were not considered as being on a par with the primary sniping rifle, but could be used in a selective fire role in case of an attack.
With the obvious merits of current self-loading sniper rifles, these weapons came to be seen as the potential equal to the bolt-action repeater in accuracy, not to mention their superiority in a target rich environment such as has been common in the G-WOT. Filling this requirement was the underlying factor of the SASS Program. The rifle itself was designated the XM110.
Without re-printing the myriad requirements of the SASS Program, the two main points of the rifle was that it was to be chambered for the 7.62x51mm NATO (.308 Winchester) cartridge, and that it be capable of semi-automatic ONLY fire. The current trend is for the sniper to transport his precision rifle slung while using an M4 or similar 5.56mm rifle for close-range defense in route, and to defend his position once deployed.
In addition to the above requirements, SASS candidate rifles were to be M1913 (“Picatinny”) friendly in terms of mounting a wide range of optics and other accessories, and be able to mount a sound suppressor and a bipod. Also specified were a “Match Grade” trigger, a 20-round magazine, an adjustable butt stock, and a high degree of accuracy.
A number of manufacturers answered the SASS solicitation with a variety of rifles based on either the AR-10 design or that of the FN-FAL. While all of these rifles, no doubt, performed well, where all categories were considered, one would float to the top, and that was the submission from Knight’s Armament Company (KAC). Each company submitted five rifles and each was subjected to a variety of testing criteria. All five samples were later returned to each company with a full performance report and only the company that submitted the rifles would see the report on how its rifles performed.
Report Card With a Gold Star
While I was not able to examine the reports of other submissions, I do have a copy of the report furnished to the winner, KAC. Among a long list of other impressive performances, the KAC SASS submission averaged 0.65-inch minute of angle (MOA) accuracy. While the rifles submitted by other manufacturers may be billed by names containing the acronym “SASS,” only the KAC rifle was given the US Military designation XM110.
After first seeing the KAC XM110 at the 2006 SHOT Show, I got a closer look at it several months later during the National Defense Industries Association (NDIA) meeting in Albuquerque, New Mexico, where I also saw it fired by Colonel David Lutz, USMC (ret.). Soon after, I traveled to KAC’s facility in Titusville, Florida, where the XM110 is produced, for an in-depth glimpse of why the rifle won the XM110 contract.
Like the original Stoner-designed Armalite AR-10 rifle built by Armalite during the early 1950’s and the AR- 15/M16, SR-25 and Mk 11 rifles that followed, the XM110 operates by direct gas instead of using a gas piston system. In all of these rifles and their many clones, high-pressure gas is directed from a port in the barrel back through a tube and into the rifle’s bolt carrier, which in this case acts as the rifle’s gas cylinder. As the hot gas expands inside the carrier, it drives the carrier rearward against the back of the rifle’s bolt, which here acts as the gas piston. As this occurs, equal gas pressure pushes forward against the bolt, thereby taking some of the rearward load away from this part and reducing the wear on its bolt lugs.
Since both the bolt and carrier travel back and forth the full-length of the operation, using the late Colonel George Chinn’s description of weapon operating systems, the above rifles could be classed as long-stroke gas cylinder and piston via direct gas.
Design, Materials and Execution
Based on Eugene Stoner’s original AR-10 design, the XM110 is the latest word in the SR-25 and Mk 11, which evolved from that 60-year old design. However, the original wellproven design is only refined and is not really changed.
The one change that could be called revolutionary is in the design of the locking lugs of the bolt. Not being interchangeable with any other AR-10 descendant, this bolt is far stronger than the original.
First appearing in KAC’s SR-15 and SR-16 rifles, these radiused locking lugs along with a balanced extractor and other features defined these 5.56mm rifles as arguably the finest AR-15 variants on the planet. While the selective-fire SR- 16 continues in production for the military, the semi-automatic SR-15 was sadly discontinued in the wake of Nine-Eleven due to expanding military requirements. Hopefully, with KAC’s giant new facility, SR-15 production will resume.
Other, less subtle changes in the XM110 include KAC’s new URX (Upper Rail Extension) system, ambidextrous magazine release and a butt stock that is adjustable for length of pull. This stock also has a monopod for elevation.
Now incorporated on all KAC Stoner-type rifles, the URX rail system locks rigidly onto the barrel by tightening a nut in a method very similar to securing the barrel of a Savage Model 110 rifle. However, the top rail of the URX is first perfectly aligned with that of the upper receiver using a special fixture, and the front sight folds down into the URX rail to become part of it, when not in use. The result is a top rail as true as a monolithic system.
Quite ingenious is KAC’s new ambidextrous magazine release. Effective, but simple, the release button on the left side is similar to that on the right, but is slightly lower and pivots to cam the release. This new ambidextrous release system will be incorporated into all KAC rifles.
Although it resembles a standard SR-25 fixed stock, the butt stock of the XM110 is adjustable for length of pull by turning a knurled wheel in the stock to extend or retract the butt plate. The vertical monopod raises and lowers the butt for elevation.
Using the finest materials available, more than thirty of the most modern CNC machines produce the components of the XM110 and other rifles, as well as the KAC XM110 Sound Suppressor and other KAC products, such as the company’s family of night-vision optics. All components are accordingly heat treated and finished in-house in order to maintain 100% quality control. The finish on the XM110 is the Army’s new Flat Dark Earth (FDE).
KAC’s Sound Suppressor
A key component of the XM110 package is the quick-attachable Knight Armament suppressor designed for it. Locating on the flash hider, this suppressor extends back to the gas block where its yoke-like locking device is pressed down to secure the suppressor to the gas block. Once mounted, the suppressor is sealed and provides a sound reduction of 30 decibels.
Optics, Bipod and Carrying Case
Virtually the only items in the XM110 package not produced by KAC are the telescopic sight, bipod and carrying case. Stemming from an “if you can’t beat’em, buy’em.” philosophy, KAC furnishes each XM110 with a Leupold 3.5-10X30mm Sniper Scope, a Harris bipod and a Hardigg Storm Case.
Leupold scopes are pretty much standard throughout the U.S. Military, as are Harris Bipods. The Leupold Sniper Scope is rugged and precise and the Harris Bipod is lightweight yet tough enough for the job, and it performs. I’ve always maintained that extra weight in a bipod is excess weight, and the Harris proves this.
A relative newcomer to the tactical scene, the Hardigg Storm Case was an easy sell, as Hardigg cases are heads above all others, and are available for a variety of items in addition to the XM110. They also come fitted for a number of firearms and their interiors can also be custom laser cut for anything that will fit in their wide range of sizes. If that’s not enough, Hardigg Cases can be had in many colors. As are virtually all aspects of the XM110 package, the Hardigg Storm Case comes in FDE color, and it holds the rifle along with spare magazines, ammunition, KAC Sound Suppressor and an Otis U.S. Military .30 caliber cleaning kit that is also standard XM110 equipment.
Speaking of triggers, did I forget to mention the KAC Match Trigger? Another standard on the XM110, this two-stage trigger is precisely made and tuned at the factory to break crisply at about 3 pounds. This weight is ideal for both safety and accuracy and is the weight I prefer for all precision rifle shooting.
At the KAC range the XM110 was fired with and without the sound suppressor, and with the suppressor mounted, ear protection was not mandatory. In fact, as far as I was concerned, ear protection wasn’t necessary at all. Recoil was mild and the rifle did not malfunction in any way during an afternoon of shooting at various targets.
The XM110 was fired prone from its Harris Bipod as well as a GPS Grip- Pod. Both worked well in supporting the rifle and the GripPod weighs but a fraction of the weight.
While only informal shooting was done by a number of people with the sample rifle, I’ve been shooting SR-25 rifles for years, and I can attest to their consistent sub-minute of angle (MOA) accuracy.
As this is written, the KAC XM110 has dropped its experimental status and has been type classified as the M110 Sniper Rifle. As such it is slated to replace all 7.62mm NATO caliber sniper rifles in the system, both selfloading and bolt-action. Only time will tell, but KAC was in full production of the rifle when I was there.
Will the M110 be available outside the U.S. Military? Yes, but only once military contracts are filled. You can buy one of the other SASS submission rifles, but not the M110, at least not yet. Also, the commercial variant may not carry the exact M110 designation, as is often common with a commercial version of a current military weapon. Either way, it will be the real McCoy and 100% MilStd.
In the meantime, the SR-25 and commercial versions of the Mk 11 in both rifle and carbine configurations are available.
This article originally appeared in the June, 2007 issue of Soldier of Fortune.