We’re new to 8.6 Blackout, and in this first look, we’re going to see just how accurate we can get at 100 yards and beyond. This year at SHOT Show, I was talking with the guys at Alpha Munitions about the 8.6 Blackout. I also had a follow-up discussion with Hornady when visiting their facility. This is a fascinating cartridge! Like a lot of heavy-for-caliber subsonic optimized cartridges, it isn’t traditionally known for extreme accuracy at 100 yards (typical expectations sit around 1.5 to 2.5 MOA). We wanted to see if we could comfortably get sub-MOA with a special rifle and an awesome load.

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About the 8.6 Blackout

The 8.6 Blackout was developed by Q. It utilizes .338 caliber bullets in a 300 Blackout-length case built on a shortened 6.5 Creedmoor/308 case body. It features a .308 case rim and is heavily optimized for short barrels (like our 12-inch test barrel) and suppressors.

It won’t fit into a standard AR-15 due to its overall length and bolt face requirements, but it can be run in bolt-action rifles or AR-10 configurations.

When you compare it to the classic 300 Blackout, which shoots projectiles weighing around 220 grains, or to the 338 ARC (which pushes 300-grain projectiles), the 8.6 Blackout takes things even more extreme by handling bullets up to 350 grains. It gives you much more punch and longer reach.

Where the 8.6 Blackout gets truly interesting is the twist rate.

Initially, Q pushed a 1:3 twist rate. In my discussions with Hornady, they noted that such an extreme twist rate can sometimes spin the bullet jacket entirely around the lead core, causing erratic results. At 1,050 fps, a 1:3 twist spins the bullet at roughly 252,000 RPM! By stepping down to a 1:5 twist, the bullet still stabilizes but the RPM drops to a much safer 150,000 RPM. This still provides aggressive yaw on impact without sitting on the absolute edge of bullet integrity. SAAMI has also included guidance for a slower 1:6 twist (126,000 RPM), which serves as a good medium ground for standard bullets up to about 330 grains.

The Rifle

The rifle we are using for this story was commissioned by Evan Hafer of Black Rifle Coffee Company specifically for close-range,big-game hunting. He has already taken two elk with it!

It is a short, compact bolt-action rifle built on an Impact 737R action with a 1:5 twist 12-inch barrel. It sits in an MDT HNT26 chassis and is topped with an Athlon Helos Gen 2 6-24×56 scope. We suppressed it with a Silencer Central Banish 46.

Reloading the 8.6 Blackout

The team at Alpha Munitions had worked up an awesome load for this exact rifle, which we replicated.

Using our RCBS Rock Chucker Supreme and RCBS 8.6 Blackout die set, we loaded brand-new Alpha Munitions brass with 285-grain Hornady ELD-M bullets over 11.0 grains of Hodgdon Lil’Gun powder (dispensed by an RCBS ChargeMaster Link).

When loading subsonic ammunition, you want to aim for a velocity window between 900 and 1,050 fps. If a single shot breaks the speed of sound, you will get a supersonic crack—which is a huge problem if you are hunting without hearing protection.

Temperature and conditions vary, so maintaining that buffer is critical. (Note: Hodgdon has an entire lineup of load data specifically optimized for subsonic loads, so always start there).

Range Results

Our first test was at 100 yards. I loaded approximately 20 rounds using the 11.0-grain Lil’Gun load. After getting the scope zeroed, I shot a five-round group.

The result was amazing. We were comfortably sub-MOA, with five shots clustering into 0.654 inches (roughly 5/8 MOA) at 100 yards! The velocity averaged 949.7 fps, and the SD was an incredibly low 6.7 fps. 

Alpha Munitions clearly did their homework, as we replicated their load on the first try with staggering success.

Things went from good to great when we pushed out to 400 yards—which is practically an ELR shot for a subsonic cartridge. Shooting off a tripod, I was able to repeatedly ring our coyote steel target.

Hitting steel at that distance with a heavy subsonic bullet sounds like someone setting off a church bell, yet the round itself is incredibly quiet. For hunting situations, this quiet performance is invaluable because follow-up shots won’t immediately spook multiple animals. I saw this first hand in South Africa. 

Conclusion

At the end of the day, we had a lot of fun loading and shooting the 8.6 Blackout.

It was our very first experience with the cartridge, and it literally could not have gone better. With the right rifle, the right load, and top-shelf components like Alpha Munitions brass, the 8.6 Blackout is highly capable of sub-MOA precision. In fact, it is great for general suppressed shooting, short barrels, tactical applications, and even close-range elk hunting. 

Get the Gear

Alpha Munitions 8.6 Blackout Brass

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Thanks,
Gavin Gear