The BMW of semi-auto match rifles.
Heckler & Koch MR762A1 Rifle
By: Jim Weiss and Mickey Davis
Heckler & Koch (HK) is a well-known, small-arms systems company that provides technologically advanced firearms, logistical support, training, and specialized services, and is a major supplier to global military, law enforcement agencies, and civilian shooters.
The HK 7.62 x 51 mm MR762A1 (MR stands for Match Rifle) is a premium-grade, semi-automatic arm with match rifle features. Like its 5.56mm counterpart, the MR762A1 is a direct descendent of the HK416/417 series, but in a semi-automatic rifle configuration.
The MR762A1 uses the HK-proprietary operating system. It is gas operated, and uses a piston and a solid operating “pusher” rod. This is used instead of the gas impingement system on most AR-15 / M16-type firearms. The operating rod gas system prevents propellant gases and the associated carbon fouling from entering the weapon’s interior, increasing the reliability of the weapon and extending the interval between stoppages. The rifle stays cleaner, and heat transfer to the bolt and bolt carrier as well as wear and tear on other critical components are reduced. This increases the service life of all parts, while decreasing operator cleaning time.
The MR762A1 is produced at Heckler & Koch’s American manufacturing facilities from both American and German-made components. It uses a barrel manufactured in Germany using HK’s well-known cold-hammer forging process. This process uses high-quality steel to produce a barrel with the spiral grooves so important for accuracy, even after firing thousands of rounds.
Unlike the HK417, the MR762A1 does not use a chrome-lined barrel. Chrome lining can sometimes mask bore imperfections and negatively affect accuracy. For the company’s new series of semi MR rifles, HK designers and engineers believe best accuracy is obtained with an unlined bore.
The unchromed barrel has an internal profile of four lands and grooves with a 1-in-11 inch twist. It is also moderately “swaged” with a slightly smaller internal diameter at the muzzle end than at the chamber end. This feature has a positive effect on the bullet accuracy and velocity. The thick, heavy contour 16.5-inch barrel also contributes to its accuracy. Used with the HK Free Floating System, the barrel does not touch the handguard, ensuring the barrel is truly free-floating for maximum accuracy.
The MR762A1 uses a C.I.P.-dimensioned chamber (a chamber with dimensions specified by the Commission Internationale Permanente). It is designed to function with a wide variety of high-quality 7.62 x 51 mm (308 Winchester) ammunition.
The HK Free Floating Rail System (FFRS) handguard was developed for the HK417. It has four MIL-STD-1913 Picatinny rails and allows all current accessories, sights, and aimers used on AR-type arms to be fitted to the MR Series. The HK rail system can be installed and removed with simple tools, and returns to zero when reinstalled. This rifle also has a Picatinny rail machined into the top of its upper receiver for mounting optics and mechanical sights. An enhanced, two-stage trigger adds significantly to the accuracy of the MR762A1, and an extended latch-changing handle makes operating the rifle with a telescopic sight easier.
According to Sam Bass, Heckler & Koch’s armorer, a swaged barrel contributes to the accuracy of the fired bullet. While other military and civilian rifles are made with swaged barrels, the overall design of HK barrels is different. The HK MR762A1 rifle is produced with a thick, match grade barrel. Thinner barrels tend to be less accurate.
HK’s match grade barrel is also not chrome-lined because chrome-lined barrels can have lesions that can negatively affect the accuracy of the rifle. These lesions can be found using a microscopic bore scope, but additional steps would add to the price of the rifle. HK strives to eliminate the barrel anomalies that might appear in other rifles. Lesions in a barrel generally refer to the production process of “Button” or “Broach” cut barrels. HK’s barrels are hammer forged and as such do not suffer this anomaly to the extent other processes produce.
A new bench-rested HK MR762A1 rifle should have an accuracy of 1 ½ inches. Bass demonstrated this using an improvised bench rest at 150 yards with a 1-4x24mm Night Force NXS scope. Higher power scopes, like 10-power, are more accurate; however, with higher power come more anomalies such as heat mirage. Accuracy improves to “one hole” shooting after firing several hundred rounds. After several thousand rounds, there might be miniscule throat erosion to the barrel. It could take in excess of 10,000 rounds before any significant shift in shot group dimension.
Bass acknowledges there may be better trigger systems on the market than the MR762A1’s two-stage trigger, but such systems would very notably increase the cost of the rifle. The rifle is already on the expensive side, and if the two-stage trigger were replaced, the firearm’s cost would increase about $500. Normally, such triggers have to be fitted and installed by a gunsmith. The HK trigger improves with rounds fired. The rifle Bass demonstrated had a trigger pull of 4.5 pounds.
A common error that shooters make is to clean a new HK firearm before shooting. These firearms come lubricated and shouldn’t be cleaned out of the box. In addition, heavy gun lubricants or gun grease should not be used on the MR762A1. Light oil is recommended on the rails or tracks and firing pin, as well as on parts that ride, like the recoil buffer and bolt carrier.
Mark Allen Prince helped conduct the field evaluation. Prince is a professor of special operations at Central Ohio Technical College and has over 23 years of experience and training in counter-terrorism and law enforcement special operations at the federal and local level. As a former SRT operator and element leader with a federal counter-terror team, Prince cut his teeth on HK products, specifically the MP5 family. His primary duty weapons were the MP5 and MP5SD.
Although the MR762A1 appears to be built on the M16 / AR-15 / AR-10 platform, it is pure HK when it comes to platform. As with all of the weapons the evaluator had used from the HK family, this rifle performed without flaw. As it uses the proprietary gas piston system found in the HK G36, the rifle eliminates most of the known issues (and sometimes unfounded fears) from the direct gas impingement systems of the standard M16 platform.
The weapon was zeroed with its provided iron sights (rear diopter and front flip-up), which are the sights that you will find on most HK rifles. The trigger is marketed as a two-stage, however the evaluator did not find the trigger to be anything spectacular when it came to creep, or let off, or reset. All in all, the rifle demonstrated excellent iron sight accuracy at realistic distances with the “pedestrian” trigger.
The HK MR762A1, like any other 30-caliber M16 / AR-15 platform rifle, feels like its little sister, the 5.56/.223—but on steroids! The fit and finish of the HK was excellent, with the pistol grip, collapsible stock, ambidextrous safety, and quad rail leaving the shooter wanting for very little.
The rifle empty comes in at almost 10 pounds! However, the evaluator found the weight manageable. It carries well, but is a bit “front heavy.” Throughout the field test, the evaluator made sure he carried it everywhere to assess its weight and ergonomics. The HK match rifle weight reminded him of a fully loaded 12 gauge with full extended tube and equipped with accessories.
The rifle requires the operator to utilize the Disassembly Tool (a 5mm Allen wrench) located in the butt stock. Prince removed the upper from the lower, removed the bolt and charging handle for a quick inspection, and ran a cleaning patch through the barrel followed with a light oily one. The Disassembly Tool is required to push in the detent located in the center of the rear takedown and front pivot pins.
The pins are designed that way to remove play, and ensure a tighter fit resulting in increased accuracy. It is no surprise this feature has been included with this weapon system. Both pins are “captive” and will remain attached to the lower so they are not lost. With regards to maintenance, all commercial HK weapon systems are serviced in the Columbus, Ga. location.
The HK MR762A1 has an MSRP of $3,995. Taking into account the technology in the rifle, its performance specifications, and who built it, the expense is par for the course. While an individual operator might find it challenging to justify its price versus another 7.62x51mm AR-15 platform rifle, an agency might not.
The Heckler and Koch MR762A1 is a fantastic weapon system that is extremely reliable and accurate. It will accommodate all the needs and desires of a serious shooter who wants to accessorize, and would be an excellent choice for an agency desiring a semi-auto counter-sniper rifle. This rifle would serve a great purpose for those in very rural areas where over penetration is not as big of an issue as it is in metro and urban environments. The H&K MR762A1 embodies the meaning of one German word “Überlegen” – superior!
Jim Weiss is a retired lieutenant from the Brook Park, Ohio, Police Department and a frequent contributor to
LAW and ORDER. Mickey Davis is a California-based writer and author.