Rock River Arms (RRA) has a terrific reputation for turning out top-notch AR-15s and AR-10s chambered for a wide selection of cartridges, including the standard 5.56/.223, .204 Ruger, 7.62x39, 6.8 SPC, and the .458 SOCOM, a real thumper, if there ever was one. RRA even has ARs in 9mm and .40 S&W pistol calibers. Want a left-handed AR, a piston gun in .223 Rem. or .300 Blackout, or fully automatic ARs for law enforcement? No problem: RRA has them, too. RRA’s 123-page catalog details a mind-boggling selection of just about anything one could want in the AR world.
RRA’s large-frame ARs are essentially AR-10 rifles, and they are available in several configurations. One of the newest versions is called the Predator HP LAR-8M. Based on features and calibers, it would certainly be a coyote’s worst nightmare. This iteration is available in .243 Winchester and 6.5 Creedmoor, and the very similar Predator HP LAR-8 is available in .308 Winchester.
The Nuts & Bolts
The Predator HP comes securely packed in a sturdy, fitted, hard-plastic case that has two provisions for padlocks, and the rifle is indeed a formidable piece of ordnance. The lower receiver is RRA’s forged LAR-8M, which is marked “multi caliber.” It has a forward assist. The upper receiver is forged and is an RRA A4 assembly. It has a flat top with numbered Picatinny rail slots for optics or back-up iron sights. The receiver is finished in hard-anodized black. The front edge of the upper receiver and the back end of the handguard match up perfectly, something that can’t be said of a lot of ARs. The chambering is laser-engraved on the upper above the ejection port.
The controls are similar to most ARs. The magazine release is ambidextrous, as is the bolt release, which is a lever in front of the trigger guard, behind the magazine well. The safety lever is on the left side of the receiver and is not ambidextrous. The trigger is RRA’s two-stage unit, and the trigger guard is the winter version for better access with gloves on—obviously handy for winter coyote hunters.
Predator HP barrels are fluted stainless steel, 20 inches in length, and bead-blasted. RRA gets its barrels from Wilson Combat in Berryville, Arkansas, and they are cut from premium blanks, button rifled, and air gauged. Then they’re cryogenically treated to remove any lingering stress. Finally, they are handpolished before the gun goes off to the customer.
In .243 and .308 Winchesters, the twist is 1 turn in 10 inches, but the 6.5 Creedmoor has a 1:8-inch twist. Two versions of the gun are available in each caliber: one with a threaded muzzle and an RRA Operator muzzle brake installed, the other without threads or a muzzle brake.
The gas system is rifle length, and the gas block is low profile. It sits inside the free-floated 14.75-inch RRA DLX handguard that also has Picatinny slots on its top and comes with three short accessory rails. The buttstock is an RRA Operator, and the pistol grip is by Hogue.
The Predator HP comes with one magazine and an owner’s manual. The rifle accepts RRA’s LAR-8 polymer magazines, which are available in three-, five-, and 20-round capacities.
I have tested other RRA ARs, and they have been top drawer, so I was delighted to receive the new Predator HP LAR-8M in .243 Win. for this review. I gotta tell you, it is no pipsqueak! It is a solid piece of hardware. Without a scope and mount, it weighs 9 pounds, 4 ounces.
The size of the magazine supplied with the rifle is not stated in the company catalog, but the one that came with my rifle was a 20-rounder. I ordered the shorter five-round magazine because I prefer it for testing and hunting.
The bead-blasted stainless-steel barrel looks elegant, and a peek with my Hawkeye borescope revealed smooth rifling and no extraneous toolmarks. In other words, it’s a typical RRA barrel. The absence of a muzzle brake was a welcome relief, as in my opinion they do nothing but produce horrendous noise. The muzzle is nicely recessed to protect the crown.
The trigger pull registered 6 pounds, 9 ounces on my Lyman gauge, and the break was very crisp. While this pull weight may seem a mite heavy for a predator-hunting rifle, in testing, I found the rifle to shoot just fine. A crisp break trumps pull weight.
I rounded up a baker’s dozen of .243 Win. factory loads and headed to my shooting building. I had one breakdown, and it was totally my fault. I outfoxed myself. I don’t like empties launched into orbit out of an AR dinging up my nicely finished drywall, so I attach a brass catcher to such rifles. This is easy on guns with Picatinny rails, like the Predator HP. Well, right off the bat, the Predator jammed, failed to eject, you name it. I was dismayed until I realized the empties were hitting the brass catcher and bouncing back into the receiver before the bolt could close. I tried a different brass catcher but had the same result. After I removed the catcher, the Predator HP never bobbled once in hundreds of test rounds.
I started each range session with the Predator HP’s barrel clean and cold. I fired one fouling shot, then fired the test rounds and allowed the barrel to cool between groups. I cleaned the bore every 20 rounds. I am delighted to report that the barrel picked up almost no copper fouling. After all the test shooting, I checked the bore with the borescope, and there was almost no throat erosion and the rifling looked like new.
Speaking of test rounds, how did the Predator HP shoot? Pretty darn well. It averaged 0.90 inch for the 13 different factory loads. Only two loads averaged over an inch—and that wasn’t by much.
Top accuracy honors came from three flyweight varmint loads. The Hornady Superformance load with the 58-grain V-Max bullet averaged 0.67 inch at a sizzling velocity of 3,598 fps. The Nosler Varmageddon 55-grain Flat-Based Hollowpoint clocked 3,580 fps and averaged 0.71 inch. And Winchester’s Varmint-X with the 58-grain Polymer Tip bullet averaged 0.87 inch at 3,527 fps. Any prairie dog within a verst would be in big trouble.
Deer loads did well, too. The Federal ammo loaded with the Nosler 90-grain AccuBond averaged 0.73 inch. This was a bit nostalgic for me, as I had the pleasure of taking the very first game animal, a Utah pronghorn, with the 6mm 90-grain AccuBond right after its introduction in 2011. The Hornady Superformance ammo with the 80-grain GMX bullet turned in a group average of 0.75 inch at 3,149 fps. Not to be outdone was Browning’s new deer round loaded with the Rapid Expansion 97-grain Matrix Tip. At, 2,887 fps, it averaged 0.75 inch.
As expected, the measured velocities of the factory loads were somewhat lower than the velocities listed by their manufacturers and varied all over the place. The smallest difference was with the Federal load with the 90-grain Nosler AccuBond (174 fps), and the largest difference was with the Remington Premier 95-grain AccuTip (395 fps). Overall, the loss averaged 7.8 percent for the 13 loads fired. This illustrates the importance of chronographing the actual velocities of a load in your rifle for long-range shooting.
This also ties in with the advantages of hunting with ARs. Most obvious is the instant availability of fast follow-up shots from a magazine. Although I think this feature is sometimes overemphasized, it can be important. For example, on a recent axis deer hunt in Texas, I was hunting with a single-shot T/C Contender G2 in 7-30 Waters; it’s a fine deer cartridge and rifle combo. A plump axis doe and yearling scampered out to the feeder. I shot the doe, but I could not get the Contender reloaded before the yearling vamoosed. With an AR in this situation, I probably could have taken them both.
Many ARs are very affordable and available in a wide variety of calibers and configurations, so there’s something for just about any hunter and game. ARs are usually very accurate and can hold their own with a bolt gun. They are reliable under extreme environmental conditions and require minimal maintenance. Plus, for do-it-yourselfers, there is an almost endless array of add-on goodies, so shooters can customize the AR to their hearts’ content.
ARs basically come in two “sizes”—the AR-15 and the AR-10—with cartridge sizes to match. The AR-15 is lighter, shorter, and chambered for smaller cartridges, but this doesn’t limit them to the 5.56/.223. The .223 Rem. is by far the most popular AR-15 cartridge, and it is used by legions of prairie dog shooters. The 22 Nosler and .224 Valkyrie are viable varmint rounds, and the .204 Ruger is a potent prairie dog buster.
While many hunters use their .223s on deer, there are better AR-15 cartridges for larger game, such as the .25-45 Sharps, 6.5 Grendel, and 6.8 SPC, among others. Also, there are a lot of wildcats for ARs that are potent and fun to work with.
The larger AR platform is the AR-10. These rifles are chambered for rounds like the 6.5 Creedmoor, .243 Win., .308 Win., .338 Federal, and other “medium-sized” cartridges. An AR-10 in .308 Win. or .338 Federal is formidable armament for deer and larger game. In addition, there are also fat .45-caliber thumpers that throw heavy bullets at moderate velocities for big game.
AR-10s have the obvious advantages of more power and bullet weight compared to cartridges for the AR-15, and while they retain the same reliability and accuracy features of the smaller AR-15, this comes with a price—and I don’t just mean dollars. The typical AR-10 is a lot heavier than an AR-15, as is the ammo, so these are factors to consider. But if the hunter is essentially a “stand” hunter and doesn’t have to tote an AR-10 too far, this is not a major problem.
Almost every AR-15 and AR-10 comes with a muzzle brake or a flash-hider. To each his own, but I certainly don’t recommend either for a hunting AR (or any shooting, actually), as the increased noise level is considerable.
Overall, I was very impressed with the RRA Predator HP LAR-8M. It shot great with a variety of loads, and it never choked. It doesn’t have a lot of sharp edges sticking out here and there to snag one’s clothes or fingers. The .243 Win. and 6.5 Creedmoor are eminently suitable for varmints and deer, and the Creedmoor is suitable for larger game or long-range shooting, so it’s versatile. About the only downside is its weight, but that’s a subjective thing. After all, it’s a full-sized rifle.