A few years ago, Sturm, Ruger & Company leaped into the crowded AR15 rifle market with a piston driven AR15 variant. The SR-556 isn’t inexpensive. However, as a result, it is a very good rifle. Later, Ruger offered what I regarded as a sensational rifle, the SR-762, a 7.62×51 NATO variant. I suppose this might qualify as an AR10, but in most ways, it is a modern design. This isn’t a gas-impingement operation but rather a piston-operated rifle with a four-position gas valve or regulator.
There are several claims made for the piston-driven action that require a lot of shooting to prove. The gas impingement system, that is standard for the vast majority of AR-type rifles, sends gas straight into the chamber as the action is operated. The piston type uses an operating rod to move the bolt and may burn cleaner and even cooler.
I have learned enough about AR15 rifles to know that there is less fouling, and overall the system seems as reliable as the original AR15 type. Piston-operated AR-type rifles are reliable but need cleaning—after all, fouling doesn’t just evaporate and must be cleaned from around the gas block.
When the piston-driven AR15 in 5.56mm was being developed, another claim made was less recoil. The 5.56mm rifle doesn’t kick enough for this to mean anything, and I cannot detect the difference, if any. Neither do I find the recoil of the Springfield M1A .308 rifle excessive. But when firing the Ruger SR-762 I do find a comfortable rifle to fire.
The Ruger SR-762 was designed to offer .30 caliber power in a rifle that remains relatively compact and easy to pack in the field. Reliability is most important, followed by ergonomics and accuracy. The 7.62×51 SR-762 offers greater power, energy and penetration than the 5.56mm NATO rifle.
The piston action features a piston that channels power through an operating rod to actuate the bolt. The SR-762, in common with the FN FAL rifle, features a gas regulator for use with different power levels of ammunition. A steel clip is overcome by moving the gas regulator with a bullet nose. The regulator uses four positions to regulate gas flow.
Position zero is no gas at all, turning the SR-762 into a manually operated rifle. I see some utility in this for those using heavy-bullet subsonic loads and a sound suppressor. Next is number one. This setting is for heavy loads and may be the setting used by enthusiastic handloaders. Two is the gas regulator position most of us will use for full power factory ammunition. Finally, number three will be used for lower powered ammunition to coax it to operate properly.
The SR-762 features a chrome-lined 16-inch barrel. The handguard is well designed and comfortable in firing. The forend will accept rail inserts and lights and lasers are easily mounted. The rifle is a flat top design that accepts fixed sights, red dot sights, or rifle scopes. I particularly like the dual aperture rear sight.
The front post is adjustable for elevation. The bolt and carrier assembly are like the AR15, but heavier. These parts are chrome plated for smooth operation and easy cleaning. Fit and finish are good.
The lower receiver accepts a wide range of AR15 standard parts including the many aftermarket triggers for the AR15 rifle. The stock is standard M4-type, six-position stock. A good touch is the Hogue pistol grip. Three Magpul 20-round polymer magazines and a zippered case are supplied with the rifle.
I have fired this rifle extensively with iron sights and find it easy to use and accurate. The iron sights offer good results to 50 yards in rapid fire and are useful well past 100 yards. I have used several types of optics including a quality AR-type scope and the TruGlo Eminus rifle scope.
The Eminus features an illuminated reticle, always a good option. The Eminus offers good ocular clarity too. The adjustment turrets allow spot-on adjustment, and the scope isn’t difficult to zero. In my opinion, the Eminus is among the best buys in the optics world.
I mounted the Eminus on the SR-762. After testing several optics for comparison purposes, I felt that it was time to settle down and give the SR-762 a permanent optic. I cracked open a box of Federal American Eagle .308 Winchester and had the rifle sighted-in in good order.
|Caliber||7.62x51mm NATO, (.308 Win.)|
|Action Type||Two-stage, piston-operated semi-automatic rifle|
|Receivers||775-T6 forged aluminum (upper and lower)|
|Barrel||16-inch 41V45 chrome-moly-vanadium steel; fluted and chrome-lined|
|Rifling||Six-groove, 1:10″ RH twist|
|Magazine||20-round-capacity detachable box|
|Sights||Ruger folding backup iron sights—elevation-adjustable post front, windage-adjustable dual-aperture rear|
|Trigger||Single-stage, non-adjustable; 8-pound, 14-ounce pull|
|Overall Length||34.75 to 38 inches|
|Weight||8 pounds 10 ounces|
|Accessories||Owner’s manual, soft case, two spare 20-round polymer Magpul magazines, three finger-groove rail covers|
|Suggested Retail Price||$2,195|
The .308 is an excellent all-around cartridge. The .308 Winchester–7.62 NATO combination has earned a well-deserved reputation for accuracy. This is demonstrated by FMJ and 168-grain MATCH loads. I also wanted to proof the rifle with a capable all-around loading. A switch hitter for both hunting and tactical use would be ideal.
I used the Federal 168-grain Tactical load with tipped nose. This is a loading that has proven accurate and reliable in the M1A rifle. After carefully sighting in the rifle, the Federal loading proved to be the most accurate combination I have yet fired in the rifle. At a long 100 yards, the rifle demonstrated 1.5-inch groups with the Federal Tactical tipped loading. That is more than accurate enough for any foreseeable chore.
The Ruger SR-762 is an excellent overall choice for those desiring a semi-auto in .308 Winchester. While the M1A SOCOM and other variants of the M1A are fine rifles that I am not giving up, the easy and familiar handling of the AR-type system make the SR-762 an excellent choice for many of use.