8.6 BLK Barrel
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Faxon Firearms has collaborated with Q to build the highest quality 8.6 BLK barrels for Remington 700 and AR10 platforms.

It should come as no surprise that Faxon Firearms is developing barrels compatible with the new 8.6 Blackout ammunition. After all, the Ohio-based manufacturer has always been at the forefront of barrel development. 

Now they’ve combined Faxon Firearms barrel expertise with the science and innovation of Q to come up with an extraordinary and formidable package.

8.6 Blackout Ammo

Here is everything you need to know about the new 8.6 Blackout round, how it compares to 300 Blackout, and the radical new barrel design by Faxon Firearms.

What is 8.6 Blackout?

The 8.6 BLK round was imagined and developed by Q. Like the 300 Blackout, the 8.6 Blackout was designed primarily for suppressed shooting, but there are supersonic loads in development as well. 

The easiest thing to do might be to imagine 8.6 BLK as the 300 BLK’s big brother – but as far more than just a simple upgrade. 

8.6 BLK Features

  • Fits AR-10 Sized Rifles
  • 338 Subsonic Load Based around the 300 grain Sierra Match King
  • Similar to 338 Federal; however, the case was shortened to work reliably with gas guns without modification to mags. 
  • Uses Standard 308 Mags
  • Low-Pressure Cartridge
  • Utilizes a shortened 6.5 Creedmoor case for the use of subsonic and high BC projectiles
  • Current Ammo Companies in Development: Gorilla, Hornady, Black Hills, and Discreet Ballistics
  • Designed Around a 12″ barrel

8.6 BLK Mags

Faxon Firearms has previously shown several 8.6 Blackout loads with a 300-grain bullet and a 210 grain Barnes TTSX bullet. These loads are still in development but should become commercially available in the foreseeable future.

How is Faxon Firearms Involved?

Faxon Firearms has been privileged to work with Q on developing the best possible barrels to support this revolutionary new round. The team at Faxon Firearms is in the development of their own 8.6 BLK barrels for both the AR-10 and Remington model 700 platforms.

Faxon Barrels for the 8.6 BLK

Faxon Firearms will be offering 1:3 twist barrels chambered in 8.6 Blackout for Remington 700 platforms and AR-10 pattern rifles. The barrels for both platforms will be available in 8″, 12″, and 16″ length options.

Faxon Firearms 8.6 BLK barrel Details

  • 1:3 twist rate
  • Better stabilization on long and heavy subsonic rounds
  • Better expansion of the projectiles
  • Re-allocates the energy from the sound and flash to the rotation of the bullet
  • .875 gas block journal for AR10
  • DPMS Gen 1 Pattern

Remage style barrels from Faxon will use a Remage style nut with a standard AR-15 armorers castle nut wrench. The nut is included.

Why is the 1:3 Twist Rate Important?

Faxon Firearms is manufacturing the barrels for these 8.6 Blackout loads. These barrels are not by any means your standard rifle barrel. Designing and manufacturing them can be challenging, but Faxon Firearms has confidently stepped up to the plate. To properly stabilize the long and heavy 300-grain subsonic projectiles, the 8.6 blackout barrels must have a 1:3 twist rate. That means the round is making one full rotation every three inches of barrel length. 

8.6 BLK vs 300 BLK

This helps the 8.6 caliber cartridge re-imagine energy on target. 

Faxon Firearms’ Barrels are slated to launch around late June or early July of 2022. The ammunition will also launch right around the same time. For more information on the 8.6 blackout project and to be notified about the availability of Faxon barrels, proceed to the Faxon Firearms 8.6 BLK page. It is dedicated to the Q collaboration. 

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    • Love the concept just wish it was in any way practical for states with suppressor bans besides novelty/hunting pistols.

  1. A friend at work has a rather large collection of AR pattern rifles, in virtually every caliber out there. It would appear that he will be adding another one to the collection.
    I will likely pass, the only reason that I got a .300 BO was to build a pistol without the muzzle blast of a 5.56 one, other than that I stick with calibers you will fine an any gun/sporting goods retailer.

    • My thoughts exactly.

      Anymore, if I don’t already have the caliber in the house, it’s a hard pass.

      I currently have “enough’ food for my dogs. Really don’t want to have to find boutique food as well.

      ESPECIALLY with the current shortages locally, I would have to order it in, raising my visibility on radar.

      • “…if I don’t already have the caliber in the house, it’s a hard pass.”

        If you have a 6.5 Creedmoor (Praise be, Gov’s St. Creedmoor!) “In the house”, er, gunsafe, you have a supply of brass available.

        Isn’t the main attraction of .300 BLK that as long as you have .223 – 5.56 available, you could ‘roll your own’, if necessary?

        • EDIT – (Or did I pick a bad time to quit main-lining Heroin? 😉 )

        • Whether you buy ammo or buy reloading dies and trimmers to roll your own, the effect is more time and money for a new round. I’m struggling with that myself right now as I picked up a refinished civilian .30 Luger the other day for basically pennies. Yes it was a good deal, yes I love Lugers, yes I may pick up a Swiss in .30 eventually. For the moment though, I’m struggling on deciding whether I want to keep it. I don’t like having guns I can’t feed and my budget is kinda tight right now.

    • That’s why I say we have no hope for change except by force. This country has been taken over by corrupt politicians for over 45 years. Everyone one that in government from the past 45 years has baggage. They all need to be put on trial and investigated.i do home work ….. 𝙛𝙪𝙡𝙟𝙤𝙗𝙯.𝙘𝙤𝙢

      • “They all need to be put on trial and investigated.”

        POS spammers like you “need to be put on trial and investigated”. (Or hunted down like the dogs you are.)

        Have a nice day, spammer! 🙁

  2. Most people with suppressors have a a 30 cal suppressor. So people have to spend another $1000 and wait just to appreciate the new subsonic 8.6. The 300 blk had the advantage of many people already having a 30cal suppressor that they used on other rifles and can QD to a 300 blk ar pistol. I see this new caliber dying very quickly.

  3. 300gr at 1070fps is 763 ft-lbs. I realize this is a suppressor focused round but I still think its really nichey. Assuming it stabilizes at 200 yards the difference between a .750 bullet and a .130 bc bullet is about 9 inches drop.

    Why not 458 Socom? What do you really gain besides weight and cost?

  4. The only industry in the USA that is innovative, growing, paying real taxes and creating real American jobs is the Firearms Industry. And half of the government wants to completely destroy it.

    Sheesh !!!!!

  5. So it’s a shortened 6.5 Creedmoor case.

    This makes me wonder about cross-chambering. That’s why I don’t have a .300 Blackout … I’d rather not have the potential for a kaboom.

    • The ‘Boom’ only happens when you put a .300 Blk in a .223 – 5.56, right?

      The other way means an anemic ‘pop’ sound and a little .556 slug rattling down a .30 cal bore, does it not?

      (I do get where you’re coming from on this, and there’s a ‘stupid tax’ to be paid for the careless. Could it actually ‘Ka-Boom’ on you and injure you? AFAIK, if you screw up, you just pay the ‘tax’ and get a memento to hang on your wall, and club to death a home invader, if needed… 😉 )

      • Theoretically a 300blk shouldn’t chamber in a 5.56. The widened neck should keep the round from chambering properly and should keep the bolt far enough back to keep the hammer from hitting the firing pin.

        Of course, all the SHOULDS in the world won’t prevent mishaps. But I tried chambering a 300blk in my 5.56 at the range in a controlled environment and my bolt wouldn’t close. I did not try the trigger as I’m only so curious. Perhaps we might get a youtuber with enough money to spend on blown up guns to give us a test

        • Wow.

          The .300 BLk slug was squeezed down (the barrel acted like a die) and was fired. And the rest of the gun was toast.

          That’s an expensive stupid tax that may even have hurt the one firing it… 🙁

  6. By the shape and weight of the bullet I think they are trying to get as high of ballistic coefficient as possible to increase the range on subsonic lethality. Could be a real winner though, a tight niche but think it as a longer range 300 blackout with less drop. The military is going to love this.

    • Isn’t this really for the CQB folks? With a can, it would make a nice bedroom rifle…

      • Yes, if you aren’t going to run short and suppressed then this would be a waste. Just like 300 blackout. If you are wanting a harder hitting supersonic AR platform there’s many other options like 6.8 SPC, 7.62×39, 6.5 creedmor, that grendel cartridge that’s some how still around…

        • 7.62×35 is a waste, huh?

          Every rifle I own is 7.62- either ×35, ×39, or ×51. Most are 300 BLK, and the AR is where it makes the most sense (you’d prefer a ×39 AR… REALLY?!). In fact, the ×39 is most at home right where it belongs- in an AK.

          And I only use one of the 300 BLK rifles for dedicated suppressed use- the others are all supersonic. And they kick ass. If I want to really reach out and touch someone- that’s what the 7.62×51 is for.

          Waste truly is in the eye of the beholder.

  7. Speaking of 338 Federal, that didn’t stick around very long, did it? It seems like everyone suddenly stopped making firearms chambered in it.

    • Know all of 2 people that use it and do hear complaints of ammo availability (not looking to buy a new die set unless its a 9×25)

  8. So, other than commercial support and branding, what does this have over 375 Raptor? Raptor was designed for sub and super use, 270 to 350 bullet weight offerings.

    Barnes 270 Grain LRX – 2.725 inches COAL

    Powder: Alliant 1200R

    Primer: CCI 250
    Brass: Starline 308 Winchester – 1st Firing
    Starting Load: 42.0 Grains
    Maximum Load: 44.7 Grains
    2075 fps with 12 inch barrel
    2285 fps with 18 inch barrel
    2335 fps with 22 inch barrel
    Sierra 300 Grain Game King – 2.715 inches COAL

    Powder: Alliant Reloader 10X

    Primer: CCI 250
    Brass: Starline 308 Winchester – 1st Firing
    Starting Load: 38.5 Grains
    Maximum Load: 40.5 Grains
    2250 fps with 20-inch barrel
    Sierra 350 Grain Match King – 2.800 inches COAL

    Powder: Accurate Arms 1680

    Primer: CCI 250
    Brass: Winchester 308 Winchester Commercial – 1st Firing
    Starting Load: 30.0 Grains
    Maximum Load: 33.0 Grains
    1825 fps with 18 inch barrel
    1725 fps with 10.75 inch barrel.

    *data from https://www.375raptor.com/load-data/

  9. Uh yeah.
    Just thinking ahead a little. the body armor is getting stronger and the rifle cartridges are getting weaker.
    45-70 is looking more promising everyday.

    • time for 243-22 or 220 Swift of 22-250 in an LR308 type platform? I’m game. Hell lets go with old fashioned 243 55 or 58gr as well.

  10. Interesting, but I predict this dying. The .338 Federal is virtually non-existent. I still have no idea what the supersonic energy levels for this are – although way, way, way less than my .338 Lapua. Also wondering what the 1:3 twist will do with supersonic – if it’s much over 1800 FPS I help but imagine it’ll be way too much twist. You can get 360 grain rounds out of a an 8 3/8″ .460 Smith Revolver to hit 1800 FPS plus – with quite a bit of recoil.

    My $.02 is that the 30 SC will have a much better chance, but I’m not rushing out to get one of those either.

    • “Interesting, but I predict this dying.”

      Probably, but with the brass being sourced from an already popular 6.5 CM round, it can linger around indefinably. A set of sizing dies lasts longer that someone will probably live.

      And I think that’s a good thing, variety, if someone wants it…

  11. I’d like to see a gun guy physicist address the notion that 1/3 spin has any significant advantage over say 1/6.5 with a 140 or 300gr .338 bullet. According to the standard stabilization calculators, 1/6.5 is more than enough. The notion that the increased twist reduces muzzle flash and report seems suspect. I tried to calculate the energy of the spin of the bullet but wasn’t smart enough to do it quickly. Is it significant? It is about 4.7x that of a 1/6.5 bullet but that may still be tiny compared to the energy from the forward velocity and does that really translate to a better terminal effect? I am not saying I think Kevin is lying but rather that I don’t understand how what he is saying could be true. I know that he is like Paul Atreides to a lot of guys and I am not trying to insult them either. Finally, why not use an an expanding subsonic bullet like the Maker. It’s accuracy isn’t match, but it’ll do out to 200yards.

  12. As far as I an concerned, this is another toy in the AR series of weapons. I am not surprised by this one being subsonic, by the 1-3 twist rate. The 300 BO is only a half decent rifle, for hunting, as a brush rifle, used at game less than 100 yrds away. It bleeds so much energy, that it is the dirt at 150 yrds, if shot level to the ground. Militarily, it would make a half decent urban assault rifle, with 110-130 grain bullets. a 338/8.6mm round is just a ploy to get you to buy something that is someone’s folly. It uses a good AR-10 platform, to buy useless barrels, to put a needlessly slow round, down range.

    • Im not sure what you are talking about. Ive killed everything up to large black bear with 300blk. That being said, the reason 338 federal pooped out was it did not have the velocity to get the 338 projectiles to expand (with the exception of the really light ones) as they are designed for magnum rounds, then you loose the advantage of the coefficient. I think this round will suffer the same fate unless manufacturers start producing 338s with thinner jackets.

      As an aside….Ive been a fan of both 300blk and 338 Federal since they were released. The longer smks in 338 have to be single loaded in a bolt gun unless I use a long action 308 and work very well.

    • Not mine in 8.6 the 3 twist was the worst looking barrel I’ve ever scoped out …especially at the chamber galling in the rifling and pits in tbe bore one large one from land to land… had to lapp it to get it somewhere near acceptable. The 3 twist is very limiting and it has a huge case capacity for only sub sonic so ya gotta search for decent loads that don’t have large velocity swings….which can be dangerous for your suppressor with a 3 twist. Like 40 grains of powder and ya only use 15 grs, makes for a lot of empty space…you definitely have to search outside the recommended loading data.. I fired 130 loads subs and supers. Take off all muzzle devices and use your magneto speed, testing supers will destroy your chronograph bayonet, cause the bullets can explode right out of the barrel (as mine did 1st super destroying the muzzle brake)…and some at 20 yards but each bullet has a different maximum rotational speed…To make sure the bullets are exiting below 1000 fps …900 fps is recommended for a can if ya don’t want it destroyed, and I’d recommend the same for a muzzle brake. Take those off for supers. And I had a Faxon 223 barrel that was pretty good but the 3 twist looked like crap, like they don’t have the proceedure or tooling mastered IMO. This is not versatile like the 300 blackout…and I’d trade Faxon back their 3 twist for a 8 twist, to be more versatile for the average shooter and use some of that large powder capacity for supers. The 3 twist is like a uncontrollable bomb with the highest velocity supers, anything slightly in front of muzzle will be hit by pieces of bullet shrapnel as it fans out in a wild pattern… shoot down a hall an bullet fragments would be in both walls…
      crowd control?

  13. I actually own a 8.6 blackout…and its a one trick pony for anything but low velocity subs, and dangerous for supers.The 3 twist can destroy your muzzle devices at supersonic speeds, as the first super exploded inside the muzzle brake, and your magneto speed bayonet will also be destroyed as bullets blow up as soon as they leave tbe comfines of the barrel. Imagine that…and the barrel was poor quality especially at the chamber…pits and galling. Cleaned it rust and slivers of metal on the patch. Had to actually lap it. Imagine that…called


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