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The Modern Sporting Rifle Afield

The Modern Sporting Rifle Afield
The Bushmaster .308 Hunter Delivers.

Of the many approaches to fielding a Modern Sporting Rifle suitable for the bulk of North American game shooting, perhaps the most straightforward taps the origin of the Stoner-AR system. The original AR-10 came into being a year before the introduction of the now-ubiquitous small caliber/small platform AR-15.

By 1956, the military T-65 cartridge developed in the early 1950s, had come out in a number of sporting rifles as the .308 Winchester but was still in search of a home for its intended purpose as a self-loading service-rifle round. By 1959, it was paired with the Springfield M14 and replaced the M1 Garand and long-serving .30-06 as the official service rifle.

The service designation now became 7.62x51mm or 7.62 NATO. As a military round, it is capable of useful accuracy out to 1,000 yards. Loaded with proper hunting projectiles, it affords sufficient energy and suitably flat trajectory for North American game out to the 300-yard range that responsible hunters consider maximum for game shots under ideal field conditions, Hook and Bullet Television to the contrary notwithstanding. The current rifles that proceed from the basic AR-10 are suitable for the full range of sporting, police and military uses and have their basic important features in common.

The .308 Hunter is pure Bushmaster—the basic full-stocked rifle with standard gas impingement and a heavy fluted 20-inch barrel free-floated in a vented aluminum handguard. It looks like a heavy-duty Bushmaster Predator or Varminter right down to the flattop rail with 3/4 risers for mounting sporting or tactical optics with standard height rails. The rifle is well fitted inside and out and the finish is an evenly applied matte black. The single feature that is not quite in sync with the overall quality (and price) of the hunter is the basic, non-adjustable trigger that lets off at a long and creepy 7+ pounds. Most serious users would immediately replace it with a match unit from Rock River, Jewell or Geissele. The Bushmaster Hunter differs from similar AR pattern .308/7.62 rifles designed for Designated Marksman programs and other tactical roles in that it is not supplied with iron sights and lacks the cheesegrater accessory rails on every surface. It actually weighs about a pound less and sports 2 inches more barrel than one such rifle popular at the moment.

We equipped the Hunter with a Leupold Mark 4 LR/T (Long-Range Tactical) 4.5-14x50mm scope with 30mm tube. Parallax and downrange focus is by side-mounted turret. The model tested was non-illuminated and equipped with the Tactical Milling Reticle with fine mili-radian markings instead of dots. The 2-pound scope brings total equipment weight to 10.5 pounds. Add another 1-1/2 pounds for the ND3x40mm Laser Genetics Green Laser Designator we used for night shooting and you arrive at substantial package to lug around Bosque County, Texas in the middle of the night.

The ND 3×40 designator works well mounted on sporting or tactical optics.
The beam can be focused to optimum intensity and to suit the field of view of the sight.

High Performance Loads

Group shooting at 100 yards and beyond both from a light Caldwell rest and bipod reveled consistent performance of 1 to 1-1/2 MOA with 5-shot groups. We used three premium commercial loads designated .308 Winchester and two long-standing standard military match-grade loads designated 7.62 NATO. The Hornady 168-grain BTHP and the 175-grain Buffalo Bore Sniper round registered nearly exactly the same velocity in comparison with NATO M852 and NATO M188LR. There was no detectable difference between the two caliber designations though early SAAMI maximum standards hold that the .308 Winchester is a 60,000-psi load—potentially dangerous in older rifles chambered for 7.62×51 and rated at 50,000 psi. Speer Reloading Manual Number 14, lists current industry standard .308 Winchester at a maximum of 52,000 CUP and develops loads to that standard. Handloading manuals say that military cases are heavier and might require reduced charges but make no further warnings or stipulations about the two cartridge designations.

The Bushmaster Hunter showed a slight accuracy edge with the 168-grain loads though the 175s, particularly the Buffalo Bore were close enough to render the difference inconsequential. Both the BB Sniper load and the NATO MII8 LR use the 175-grain Sierra Boattail bullet the loading coming into favor because velocities remain above the de-stabilizing transonic range at 1,000 yards. The ballistic tables I constructed with both bullet types bear this out as the 168-grain BTHP with a ballistic coefficient of .450 averaged right at or just over the Mach I velocity while the 175-grain bullet with a BC of .505, remained comfortably above (1,141 fps vs. 1,243 fps).

When you want something done right, get somebody else to do it. This is particularly true when you have one of America’s top competitive Service Rifle competitors on tap and he lives on his own 1,000-yard rifle range. Stan Jarosz became a consultant with the United States Army Marksmanship Unit, one of several NRA High Power master class shooters who operated the first Squad Designated Marksman programs training selected soldiers in advanced marksmanship with higher caliber weapons prior to deployment to Afghanistan and Iraq during “Iraqi Freedom.”

He is a distinguished member of the Texas State Rifle Association Team and actively involved in training Junior ROTC teams to participate in the National Matches at Camp Perry. A long-term user of Bushmaster ARs, Stan was eager to put the current rifle and the Leupold Mk 4 scope though their paces. Shooting from prone and a Caldwell bipod from 100 and 300 yards was basically an exercise in confirming zero and the integrity of the windage and elevation adjustments. At 500 yards, Stan’s internal ballistic computer came into play as did his ability to read wind direction and velocity from observing heat mirage in the scope. At that distance, the 168-grain boattails drop 66 inches below 100-yard zero and drift 23 inches with each 10 mph of wind. Stan anticipated and dialed in the proper deflection, landing a 1-MOA group with the M118LR load and a 1-1/2-MOA spread with the M852 on a rattlebattle target. By this time, he was thoroughly impressed with the Leupold scope. We were shooting at known distances but the TMR reticle has sub gradients that allow accurate range estimates against objects of known size. The optics are clear and the adjustment values are positive, accurate and repeatable. The scope boasts full adjustment ranges of 100 MOA and shooting from 1,000 yards confirmed the integrity of the system at that range. Stan’s computations were close to the mark and he talked me onto several hits on a 22-inch wide metallic gong.

Stan Jarosz confirming zero from 300 yards. We had a near-ideal
shooting day with winds variable at less than 10 miles per hour.

Night Work

We checked out the Bushmaster Hunter with two Laser Genetics variable focus green laser designators. The ND 3X 40 clamps directly to the scope body with a double-ring adjustable mount. It is fairly easy to bring the beam in sync with the scope though the system is subject to becoming loose under field conditions—a circumstance requiring vigilant attention.

It appears that these sturdy units represent a significant advance in nighttime shooting. From the prone, I found a Birchwood Casey hog silhouette, actually about the size of a javalina, to be quite visible and easy to hit at 200 yards. Stan was extremely impressed with the hand-held ND-5×50 with sliding focus. He was amazed by how clearly this light saber illuminated the pig target for shooting from the bipod at 300 yards. While I didn’t encounter any legal varmints or nocturnal pigs, I did observe a number of deer using both designators. The animals did not react to or shy away from the green laser at all.

The quality, function and overall appearance of the current Bushmaster is fully equivalent to those produced under its original corporate structure. Stan Jarosz pronounced the Bushmaster Hunter “ready for duty” with the strong expectation that I would pass along his opinion that it needs a factory-standard, crisp 3.5-pound trigger.
By Mike Cumpston

Birchwood Casey
7900 Fuller Rd.
Eden Prairie, MN 55344
(952) 937-7933
www.gunsmagazine.com/birchwood-casey-laboratories

Buffalo Bore Ammunition
P.O. Box 1480
St. Ignatius, MT 59865
(406) 745-2666
www.gunsmagazine.com/buffalo-bore-ammunition

Federal Premium Ammunition
900 Ehlen Dr.
Anoka, MN 55303
(800) 322-2342
www.gunsmagazine.com/federal-premium-ammunition

Hornady
P.O. Box 1848
Grand Island, NE 68802
(308) 382-1390
www.gunsmagazine.com/hornady

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