Anyone have any interest in the 8.6 Blackout?

[nortac]

The 8.6 BO is basically a Creedmoor necked up to .338 caliber and can be used in an AR 10 or bolt action with a .308 bolt face so only a barrel change is needed. Longer lethal range at subsonic velocities on large game than what the .300 BO offers. Uses a VERY fast twist rate of 1:3. Bonded or solid copper bullets required or the bullet will come unwrapped as it leaves the muzzle. The fast spin increases lethality at subsonic velocity. Anyone considering jumping on this round?

 

[David57]

What animals would this be used for?
twist rate of 1:3 what powders are they using?

 

[nortac]

Large game, I believe it's been even used on Cape Buffalo. I don't know what powder has been used, particularly for subsonic loads.

https://www.shootingtimes.com/editorial/86-blackout-cartridge-review/495837#replay

 

[nortac]

S'more info:

8.6 Blk reloading info - https://www.snipershide.com/shooting/threads/8-6-blk-reloading-info.7125253/

 

[Kentos]

Interesting to say the least. Guys in free states that allow suppressor use would probably be very interested.

 

[nortac]

Certainly a niche cartridge. You wouldn't be able to walk into your LGS and grab a box of ammo, at least for now. Pretty much reloaders only.

 

[nortac]

Reading some of the early posts on the Sniperhide links above, suggests that it is a bit labor intensive to reload, at least until factory brass is available and monolithic or bonded .338 projectiles are a bit expensive. Not a plinker's cartridge for sure! Still looks like a lot of fun. Don't know if I'll get into it yet or not. The build of the gun would be easy enough and not too expensive. The only real issue would be ammo costs. And then there's the cost of a .338 compatible suppressor.

 

[David57]

What ever happened to 338-308?

 

[nikonNUT]

So the 1:3 twist thing is a gimmick "devoloped" by Kevin. Something about more energy on target due to the high RPMs of the bullet. The down side is some jacket sheding down range. I've been following a few fellas that have been developing loads and most of them are getting plain old 1:9.5 5R sticks and having them cut down to shorties and machined for ARs or bolt guns. The round intrigued me for a while. Then I realized that a 300gr .338 high BC bullet doesn't have much more *** than a 240gr. .30cal at the same 1100FPS. To add insult to injury those fancy .338 bullets aren't really made for sub-sonic applications so the perks they offer are kind of lost aren't they. Sure Kevin killed a Cape Buffalo with a 8.6 Blackout but it was a super not a sub and I doubt that is pleasant out of a 12" barrel and LOTS of powder is wasted.
300gr .338 at 1100FPS = 806 FPE
240gr .308 at 1100FPS = 587 FPE
410gr at 1075FPS = 1052 FPE (for reference this is the Hornady Sub-X .45-70 sub-sonic load)

It's neat, it's gimmecky, and the Q fan bois will love it but I'll stick with a .300BO or .45-70 sub for simplicity and cost. Add that the barrels are from a company that starts with an "F" and appear to be rifled with a hammer and chisel and its a hard pass.

@nortac You can get ammo from Gorilla at the moment. As for a suppressor either a SiCO Hybrid 46 or a Deadair Primal with a 9mm end cap will do nicely. Suppresses my .338 Lapua Magnum and my .45-70 nicely so a sub 8.6BO shouldn't be a challenge.

@Shakey-and-twitchy I think it became the .300 Norma Mag. Not really but you get the gist. .338 Norma Mag is sorta kinda a .338 AI (But a more efficent case) and the .300 Norma Mag is the .338NM necked down to a .30 cal bullet.

 

[nortac]

@nikonNUT , thanks for your input, I figured you might have some insight!

 

[Hohn]

What ever happened to 338-308?

I’m not sure if you mean 308 necked up to 338 (338 Federal) or 338 necked down to 308, begging the question of to which 338 you are referring.

338 Federal cannot use extremely heavy .338 bullets because 1) the twist is too slow and 2) the bullets are too long to be seated in the case within OAL limits.

One could think of the 8.6 as a 338 federal case with the shoulders pushed way back so that a huge bullet can be used and fit within common AR10 mag length (~2.8”).

 

[Hohn]

So the 1:3 twist thing is a gimmick "devoloped" by Kevin. Something about more energy on target due to the high RPMs of the bullet. The down side is some jacket sheding down range. I've been following a few fellas that have been developing loads and most of them are getting plain old 1:9.5 5R sticks and having them cut down to shorties and machined for ARs or bolt guns. The round intrigued me for a while. Then I realized that a 300gr .338 high BC bullet doesn't have much more *** than a 240gr. .30cal at the same 1100FPS. To add insult to injury those fancy .338 bullets aren't really made for sub-sonic applications so the perks they offer are kind of lost aren't they. Sure Kevin killed a Cape Buffalo with a 8.6 Blackout but it was a super not a sub and I doubt that is pleasant out of a 12" barrel and LOTS of powder is wasted.
300gr .338 at 1100FPS = 806 FPE
240gr .308 at 1100FPS = 587 FPE
410gr at 1075FPS = 1052 FPE (for reference this is the Hornady Sub-X .45-70 sub-sonic load)

It's neat, it's gimmecky, and the Q fan bois will love it but I'll stick with a .300BO or .45-70 sub for simplicity and cost. Add that the barrels are from a company that starts with an "F" and appear to be rifled with a hammer and chisel and its a hard pass.

@nortac You can get ammo from Gorilla at the moment. As for a suppressor either a SiCO Hybrid 46 or a Deadair Primal with a 9mm end cap will do nicely. Suppresses my .338 Lapua Magnum and my .45-70 nicely so a sub 8.6BO shouldn't be a challenge.

@Shakey-and-twitchy I think it became the .300 Norma Mag. Not really but you get the gist. .338 Norma Mag is sorta kinda a .338 AI (But a more efficent case) and the .300 Norma Mag is the .338NM necked down to a .30 cal bullet.

Well said. It’s sort of gimmicky and there’s definitely a kool-aid drinking aspect of this where you have to be shooting subsonic and suppressed to be cool.

There are many better options IMO if you want to shoot subsonic suppressed and have more power. For example, a wildcat called the 45 Raptor is essentially a 460SW magnum but with a .308 bolt face. It will feed and cycle in an AR10 and uses common .451 bullets. Instead of shooting pricey bullets with absurdly high spin rates, the 45 Raptor shooting plain hardcast big bore revolver bullets, but well over 300gr is commonly available. The case reloads with standard 460/454 dies and uses the same load data as those cartridges. Muzzle brakes recommended.

While it’s true that the larger bore 45 Raptor gives up a significant ballistic coefficient, BC is not very important at subsonic speeds and for the expressed usage of the cartridge. There’s a guy on youtube showing his coyote kills with teh 45 raptor at many hundreds of yards— it seems not to hinder him at all.

If one wants to shoot expensive bullets at subsonic speeds with a suppressor and have devastating terminal effect, it seems to me this guy’s setup eats the 8.6 for lunch:

 

[David57]

I’m not sure if you mean 308 necked up to 338 (338 Federal) or 338 necked down to 308, begging the question of to which 338 you are referring.

338 Federal cannot use extremely heavy .338 bullets because 1) the twist is too slow and 2) the bullets are too long to be seated in the case within OAL limits.

One could think of the 8.6 as a 338 federal case with the shoulders pushed way back so that a huge bullet can be used and fit within common AR10 mag length (~2.8”).

308 necked up to 338. My reloading magazines are pretty old.

 

[Hohn]

308 necked up to 338. My reloading magazines are pretty old.

Yeah, that's the 338 Federal. IMO a vastly underrated load for short range hunting. Because it uses light-for caliber bullets, it's not a long range option but inside 300y where I'd argue most hunting occurs, it smacks really hard. Like 7 rem mag with a bigger hole. It's very effective with 180s and I think up to 200gr or so.


Anything that can use a 308 can use a 338 Federal or 358 Win, although the 338 is quite a bit more powerful than the 358 win.

I've thought about building a 338 Upper for my AR10 but honestly 308 does everything I need to do so I can't justifying indulging my curiousity on it.