Bushmaster 308 AR

bushmaster-308
In 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 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.
.308_barrel
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.

leupold-mark-4-lrt-4-5-14x50mm-illum-mil-dot-riflescope-custom-67960-mainWe 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.

ND_3x40The 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 LOADSCaldwell_Rest
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.

bulletThe 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).

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.

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.

Source:Mike Gumpston-GunsMagazine

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