It was almost two decades ago that I took an
intense interest in big-bore AR rifles; first the 499 Leitner-Wise
and then the 50 Beowulf. Both were
based upon the idea of firing a fifty-caliber bullet from the
AR-15 platform. I settled upon the Beowulf, and have
been well-satisfied with it, using it on hogs and black
bear with great success. A half-inch diameter bullet
weighing between 350 and 400 grains and traveling just under
2000 feet-per-second (fps) works handily on large critters,
which has been the success of the Beowulf cartridge and the
rifle which fired it. Now, the new 500 Auto Max cartridge and
the AR500 rifle takes it a step farther, delivering higher
velocities and flatter trajectories from a rifle of similar
design.
The AR500 is built on the larger AR-10
platform, but has the magazine well modified to work with a
smaller magazine than that which is required for 7.62x51mm/308
Winchester class cartridges. The 500 Auto Max cartridge is
basically a 500 Smith & Wesson
Magnum with the rim milled off, so that it will feed
reliably from a box magazine. The rifle is produced by Big horn
Armory in Cody, Wyoming, and the ammunition is produced by
Buffalo Bore Ammunition in Salmon, Idaho using Starline
cartridge cases. Both companies worked together on this project,
producing a fifty-caliber semi-auto cartridge that produces
velocities exceeding those of the Beowulf cartridge. The 500
Auto Max beats the Beowulf velocities for any given bullet
weight by between 235 and 340 feet-per-second (fps).
I
fired the three different Buffalo Bore loads over my chronograph
to check velocities, and the results were either pretty close or
even exceeded the velocities listed by Buffalo Bore. All
velocities were checked twelve feet from the muzzle of the Big
Horn rifle, at an elevation of 541 feet above sea level, with an
air temperature of ninety-one degrees Fahrenheit with humidity
in the ninety percent range. Typical Tennessee Valley
Summertime. Velocities are listed in the chart below. Velocities
are listed in feet-per-second. Bullet weights are listed in
grains. JHP is a jacketed hollowpoint bullet. JFN is a jacketed
flat-nose bullet. HCL is a hard-cast flat-nose lead bullet. Also
listed are 50 Beowulf velocities checked on the same day under
the same conditions. The Beowulf ammunition was fired from an
Alexander Arms sixteen-inch barrel.
Ammunition |
Bullet Weight |
Velocity |
500 Auto Max
|
|
|
Buffalo
Bore JHP |
350 |
2260 |
Buffalo
Bore JFN |
400 |
1930 |
Buffalo
Bore HCL |
440 |
1911 |
|
|
|
50 Beowulf
|
|
|
Alexander Arms |
334 |
1922 |
Alexander Arms |
400 |
1697 |
Recoil, while noticeable, was not painful at
all. The rifle does back up a bit when the trigger is pressed,
but the recoil is straight-back, and doesn’t slap the
shooter’s cheek at all. The nearly ten-pound rifle soaks up
the recoil very well. Even the 440 grain Buffalo Bore load was
easy to shoot. The rifle packs a lot of power, and getting back
on target after the shot is quick and easy. Functioning with the
factory Buffalo Bore ammunition was flawless. I did experience a
couple of failures-to-extract with the bulk ammo I had on hand,
but I do not know what components were used in assembling those
loads. The AR500 doesn’t really recoil any harder than does
the 50 Beowulf; even though the 500 AR has more power than the
Beowulf, the gun weighs about two and one-half pounds more,
which soaks up the extra recoil.
The eighteen inch barrel measures .865 inch
diameter just forward of the handguard, and is threaded and
fitted with a muzzle brake. The barrel is rifled one turn in
twenty-four inches. The twelve and five-eighths-inch length
handguard is aluminum, and wears a full-length Picatinny-spec
rail its entire length on top, with three other small rail
sections screwed on at the 3, 6, and 9 O'clock positions. These
small rail sections can be moved to various places on the
handguard, if desired. The metal is finished overall in a matte
black. The AR500 rifle wears ambidextrous safety levers and bolt
catches. The magazine catch is of the high-profile extended
type. The rifle ships with one five-shot magazine. The
six-position adjustable buttstock is better than most of its
type; easy to adjust, and comfortable to use. Most telescoping
buttstocks pull the hair out of my face, but I had no trouble at
all with this one.
Accuracy was excellent! The big 500 would
cluster five shots into one ragged hole at fifty yards, and
would do almost as well at one hundred yards, shooting from the
bench using a Target Shooting, Inc. Model
500 Rifle Rest. I like the Model 500 for ARs, as the
extended magazines cause no problems or interference. For all
accuracy testing, I mounted a Leupold
HOG low-magnification variable scope. This is an excellent
scope sight for such a rifle, and can easily withstand the
recoil from this AR500.
The Big Horn rifle is a reliable and accurate
AR-based weapon for hunting large game whether up close and
personal, where a fast succession of shots might make the
difference between a good hunt and a really bad day, or out to
extended distances. The Big Horn AR500 can handle it. The big
AR500 ammo packs enough power to handle any game on Earth, and
with a magazine full of cartridges available as fast as one can
press the trigger, the Big Horn rifle can deliver that power on
target quickly.
Check out this and other Big Horn products
online at www.bighornarmory.com.
For
top-quality ammunition, go to www.buffalobore.com.
Jeff
Quinn


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