The 8.6 Blackout round is one of those cartridges that has caught my attention for a while, but I haven’t had any opportunities to shoot it. It wasn’t until this review that I got to spend time behind an 8.6 BLK AR-10 rifle and test various ammunition loads. The ammunition blew my mind as the bullets are as long as the brass casings they’re seated in. I have a few friends who hunt hogs and other predators with this cartridge, and I now understand why it’s the perfect load for the job. Let me share the history of how the cartridge came to be and what makes it so powerful for hunting wild game.
The 8.6 Blackout History
The invention of the 8.6 Blackout round originated with Q, LLC and its founder, Kevin Brittingham. The team at Q took a 6.5 Creedmoor casing, shortened it, and then necked it up to accept a .338 (8.6mm) caliber bullet. The goal was to create a round more powerful than a .300 Blackout and one more effective for hunting big game. Not only does the 8.6 BLK generate more power than a .300 BLK round, but a short-barreled 8.6 BLK can also deliver more energy on target than a longer-barreled .308. Brittingham easily demonstrated the cartridge’s effectivenessby hunting and harvesting Cape buffalo, lions, kudu, zebra, and other tough African animals.
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8.6 Blackout Twist Rate
One of the “WOW factors” of the 8.6 BLK round is that the twist rate is 1:3, compared to the usual 1:7 or 1:8 twist rates of most bullets. The 1:3 twist rate helps stabilize 8.6 BLK bullets quickly, making the cartridge well-suited for short-barreled rifles. This rapid spin rate does require specialized bullets to be used, such as bonded or solid copper bullets, as standard jacketed bullets can disintegrate upon exiting the barrel. The fast spin rate is what makes the bullet so powerful when impacting a target. Brittingham calls it the “Blender Effect” to describe the wound channel of an 8.6 Blackout on wild game or ballistic gelatin.
Effective Range
One of the most important considerations when choosing a cartridge to hunt with is understanding its effective range. In general, I recommend 300 yards and in for the 8.6 Blackout, especially with subsonic ammunition. That said, it can be effective out to 400-450 yards with supersonic ammunition because of its higher velocity. There is no question about the effectiveness on animals. Many people have proven that it can take down medium to large game with ease.
Faxon Sentinel 8.6 Blackout
My friends over at Widener’s had a Faxon Firearms Sentinel AR-10 chambered in 8.6 BLK in their arsenal that they loaned me for this review. Faxon manufactures the 16-inch barrel featuringthe brand’s Big Gunner Profile. Faxon’s Gunner profile combines the durability of the Government profile with the weight savings and maneuverability of the Pencil profile. The Big in Big Gunner refers to large-frame AR-10 platforms (.308 or similar). If you aren’t familiar with Faxon, they manufacture some of the most accurate barrels in the industry. While this rifle is outfitted with a 16-inch barrel, Faxon manufactures 8.6 Blackout barrels in various lengths, profiles, finishes, and in different materials.
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I would describe this rifle as a high-end AR-10. Everything on this gun was smooth and made with good-quality components. The Faxon G2 Superfinished AR-10 bolt carrier group (BCG) was one of my favorite components of the build. The action was buttery smooth, even when shooting the rifle suppressed with various ammunition loads. The Hiperfire Enhanced Duty single-stage trigger was another one of my favorite components on the Faxon Sentinel. It especially helps to have a smooth trigger on a hunting rifle to ensure there is minimal movement of the gun when it’s time to make the shot.
Hardware Details
The Faxon Sentinel AR-10 comes with B5 hardware. The B5 pistol grip fits a wide range of hand sizes and is one of the most widely used products among rifle manufacturers. The B5 precision collapsible stock is a must-have on a hunting rifle, especially for long-range shooting out to 300-400 yards. The ability to adjust the stock based on scope height, having the right cheek weld, and changing the length of pull to customize it for the shooter is crucial.Adjustability in a stock is a non-negotiable for me on rifles used for long-range shooting and hunting.
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The Faxon G3 Aluminum Streamline M-LOK handguard has ample M-LOK slots for mounting accessories and an uninterrupted MIL-STD-1913 Picatinny rail. Finally, the Sentinel is outfitted with an ambidextrous charging handle and safety selector. These two components are what make or break a gun for me. At the very least, I think every rifle should be equipped with these two ambidextrous controls.
Suppressor is a MUST-HAVE
Overall, my biggest takeaway from shooting this rifle is that a suppressor is a must-have for an 8.6 Blackout. The felt recoil without a suppressor doesn’t make it easy to make fast follow-up shots. You’d also absolutely have to use hearing protection even when hunting. Fort Scott sent me a couple of boxes of ammunition, and Widener’s also pitched in with extra Fort Scott ammo, as well as some heavier loads from Gorilla Ammunition.
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After shooting a few 235-grain rounds through the gun, I realized I needed to mount a suppressor to it. The Faxon MuzzLok 8.6 BLK 3-Port Muzzle Brake that comes on the gun does its job and is a good brake, but shooting this specific caliber is ten times better suppressed. Once suppressed, the heavier, subsonic ammunition is the most pleasant to shoot, with next to no felt recoil and very little sound.
The suppressor I mounted to the Faxon Firearms Sentinel was the Dead Air Primal, a multi-purpose .46 caliber silencer like no other. It is full auto rated, with no barrel restrictions,and is ready for use with anything from 9mm to .45 ACP, and 45-70 to .338 Lapua. The Primal is compatible with Nomad, Wolfman, and Ghost mounts. The suppressor weighs just over a pound and is 7.9 inches long, with a 1.618-inch diameter. Like I said, once suppressed, the rifle is a joy to shoot, and hearing protection becomes less important with how quiet the silencer is when paired with subsonic ammunition.
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M18x1.5 AI Thread Pitch Pattern
The team over at Widener’s had previously worked on an 8.6 Blackout project using this same firearm and were told by a staff member at Faxon Firearms that the barrel had 5/8×24 threads. This was not the case, and I found out the hard way that the 8.6 Blackout thread pitch pattern is actually M18x1.5 AI, which I had never heard of. I called up my SOT, Tennessee Silencer, to see if they had a HUB Fixed Mount in this pattern compatible with my Dead Air Primal silencer. They said they sell maybe one of these a year and always have to special order it since it’s not a common request. I had to pause on this review and wait over a week for the fixed mount to ship so I could mount the suppressor.
Optic Selection
Since the 8.6 Blackout is primarily used for hunting, I wanted to mount a simple, MOA-style reticle for easy holdovers. The EOTECH Vudu 1-8×24 riflescope is a second focal plane scope that has an HC3 MOA reticle in your choice of green or red. The holdovers illuminate, and acenter dot illuminates for dead-on precision. EOTECH is known for its high-quality glass and durability, making it ideal for a hog-hunting rifle. It has a smooth magnification ring and comes with a throw lever. I used the Midwest Industries MK2 QD 30mm Scope Mount with the EOTECH Vudu riflescope and was able to mount the Burris FastFire E red dot optic on the mount as well.
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Midwest Industries designed the MK2 scope mount so that the ring caps can mount a 90-degree or 45-degree red dot with the scope. These are available in various footprints for compatibility with many red dot optics. The purpose of the Burris FastFire E is to have a zero for closer range targets, anywhere from 25 to 50 yards. The red dot is much faster to acquire than looking through a scope, allowing for rapid follow-up shots. The Vudu scope can then be zeroed at 100 yards and used for longer-range shots.
Targets & Set-up
I set up a Caldwell Orange Peel ‘Sight-In’ Target downrange to start the process of sighting in the rifle and performing accuracy testing with various loads. I used the Caldwell Lead Sled DFT 3 to keep the firearm completely stable and locked onto a bullseye while I fired a few shots. This lead sled has been lovely to use on the range with various rifles for sighting in optics and performing accuracy tests. It’s easy to fine-tune the muzzle direction and adjust the height from the front and rear of the rifle. I zeroed the gun with 235-grain ammunition and was ready to dive into the accuracy testing.
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Ammo & Accuracy Testing
I tried three types of ammunition with very different grain weights and was surprised not just by the accuracy, but by the felt recoil and sound shooting through the Primal silencer. The Fort Scott Munitions 235-grain 8.6 Blackout TUI ammo was not unpleasant to shoot, but it definitely resulted in significant felt recoil and was louder than the subsequent loads. The Fort Scott Munitions Sub-Munition 285-grain ammo grouped the best and was an improvement in terms of recoil and sound compared to the 235-grain. The final ammunition I shot was the Pork Shredder, 342-grain Expanding Subsonic Hunting Ammunition in the Punisher Series from Gorilla Ammunition.
The bullet on this cartridge was designed to shred and punish, no pun intended. The weight of this cartridge compared to the lighter grain ammo is significant enough to notice the difference just in your hand. The felt recoil went down to next to nothing, and the bolt cycled noticeably slower. The Primal silencer took out just about all the sound when firing the 342-grain ammunition. There was no need for hearing protection at all when shooting this load. It didn’t group as well as the Fort Scott Munitions and would be a load I would use for closer-range hunting. The Fort Scott Munitions bullets are more precise, especially with their pointed tips that cut through the air more effectively, making them better for farther shots.
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Closing Thoughts
After spending real time with the Faxon Firearms Sentinel 8.6 BLK AR-10, it’s clear this platform isn’t just a niche experiment—it’s a purpose-built hunting and hard-use rifle that fully unlocks what the 8.6 Blackout cartridge was designed to do. From the Big Gunner barrel profile to the buttery-smooth G2 BCG and the fully ambidextrous controls, every component on the Sentinel feels deliberate, rugged, and ready for field work. Pair that with the right suppressor, quality glass, and heavy subsonic ammunition, and you’re holding one of the most enjoyable, capable hunting rifles available today. More importantly, the 8.6 BLK itself proves far more than a ballistic curiosity. Its devastating terminal performance, surprisingly soft recoil when suppressed, and effectiveness on medium to large game inside realistic hunting distances make it a cartridge worth taking seriously.
Whether you’re a dedicated hog hunter searching for a short-range hammer or a shooter who simply appreciates a modern AR-10 that punches well above its weight class, the Faxon Sentinel delivers a system that’s smooth, accurate, and impressively refined. Yes, the thread pitch hiccup and the need for a proper suppressor mount are small hurdles. But once everything is dialed in, the rifle becomes an absolute pleasure to shoot. If you’ve been curious about the 8.6 Blackout or want a hunting setup that offers both innovation and brute-force on-target effect, the Sentinel is a standout option. This rifle, and the cartridge it chambers, are far from a fad. They’re the next evolution in practical, hard-hitting AR-10 performance, and the Sentinel proves just how capable that evolution can be.
Faxon Firearms Sentinel 8.6 BLK AR-10 Specifications
- Caliber: 8.6 BLK
- Action: Semi-Automatic
- Barrel: Faxon 16 inches Big Gunner Profile, 4150 CMV, Nitrided
- Twist Rate: 1:3
- Gas System: Carbine-Length
- Muzzle Device: Faxon MuzzLok® 8.6 BLK 3-Port Muzzle Brake
- Thread Pitch Pattern: M18x1.5
- Trigger: Hiperfire EDTDM Single Stage Trigger
- Weight: 9.33 pounds
- Length: 36 inches
- Ambidextrous charging handle and safety selector
- MSRP: $2,399.00
Faxon Firearms Sentinel 8.6 BLK AR-10 Accuracy & Chronograph Data
| Fort Scott 235-grain | |
| Average Velocity | 1,621 FPS |
| Best Group | 0.71 inches |
| Fort Scott 285-grain | |
| Average Velocity | 1,117 FPS |
| Best Group | 0.57 inches |
| Gorilla Ammunition 342-grain Subsonic | |
| Average Velocity | 1,083 FPS |
| Best Group | 1.59 inches |
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