8.6 BLK Thread

[DadSmith]

Looks like a 40 Super with a much longer neck. Cute project.

The important thing to remember about the 8.6 is that it's rotational velocity from a 1:3 twist significantly increases energy on target. A 1:6.5 barrel in the Razerback wont get that.

What is the speed of the rotation. I read it somewhere but have forgotten. I remember it being crazy fast.

 

[Aszerigan]

What is the speed of the rotation. I read it somewhere but have forgotten. I remember it being crazy fast.

Bullet RPM = MV X 720/Twist Rate (in inches)

For a subsonic - 1050 x 720/3 = 252,000 rpm (300gn Matchking)
For a supersonic - 1970 x 720/3 = 472,800 rpm (210gn Barnes TSX)

For comparison -
308 supersonic - 2800 x 720/12 = 168,000 rpm

 

[Jarvitron]

My 12" 8.6 just got approved and I need to go pick it up, I am v. excited.

 

[indyblue]

Bullet RPM = MV X 720/Twist Rate (in inches)

For a subsonic - 1050 x 720/3 = 252,000 rpm (300gn Matchking)
For a supersonic - 1970 x 720/3 = 472,800 rpm (210gn Barnes TSX)

For comparison -
308 supersonic - 2800 x 720/12 = 168,000 rpm

Wow, that is pretty fast. Are those jacketed rounds if they are I’m surprised they can survive spinning that fast. That’s faster than a turbo charger impeller.

 

[Jarvitron]

Wow, that is pretty fast. Are those jacketed rounds if they are I’m surprised they can survive spinning that fast. That’s faster than a turbo charger impeller.

I've seen some lively debate about if you should use jacketed bullets at all, and I think a good argument to be made that for supersonics you should just go all-copper only.

 

[rb288]

I say go for it.

The Hybrid 46 is 0.95" shorter than the Porq Chop so there's a better chance of a strike on a longer can. With the exit aperture being the same, it should be perfectly safe. And yes, it will be more quiet.

FYI......
The 30 cal endcap works just great and actually seems to be quieter than the porq chop on the 16" bolt gun with supers.
Just thought you might like to know.

 

[Aszerigan]

FYI......
The 30 cal endcap works just great and actually seems to be quieter than the porq chop on the 16" bolt gun with supers.
Just thought you might like to know.

Excellent. Great news. :-)

Thanks for letting me know. What muzzle device are you using? 46cal ASR?

 

[Aszerigan]

I've seen some lively debate about if you should use jacketed bullets at all, and I think a good argument to be made that for supersonics you should just go all-copper only.

Never use jacketed bullets for supersonic 8.6. Solid coppers only. Jacketed bullets will explode on exiting the barrel.

They're fine for subsonic. I shoot them daily.

 

[Aszerigan]

My 12" 8.6 just got approved and I need to go pick it up, I am v. excited.

 

[rb288]

Excellent. Great news. :-)

Thanks for letting me know. What muzzle device are you using? 46cal ASR?

No, the .338 asr brake.

 

[profjeremy]

Interesting video highlighting the performance of subsonic 8.6 Blackout hunting ammo

 

[profjeremy]

Got my first chance to shoot some suppressed subsonic 8.6 Blackout this past week and I’m a believer! I used 342 grain Gorilla “Pork Shredder” ammo out of a 12” barrel with a Q Porq Chop suppressor. Here are some of my initial, non-professional thoughts:

• For what it is, it’s amazingly quiet. I shot it right after some 300 BLK and think it may be very slightly louder or the same in terms of decibels, but it has a lower tone, so it sounds a little quieter than 300 BLK, if that makes any sense.
• This subsonic round should be very effective on any creatures you can find in Indiana (and probably way beyond)! I shot the first shot into the ground and tried to find the bullet, as they open up like a mini blender blade. Shooting into compacted clay soil, it was a small hole for maybe 1 1/2 - 2” and then opened up into an inch wide channel in the dirt. I dug down a foot or so and never found the bullet. Pretty impressive, especially with the soil density!
• I was pleasantly surprised with the accuracy. Once I got used to the gun, trigger, etc. I was able to put 3 rounds in a group about the size of a quarter from 40 yards away. I’m far from the best shooter, so that’s pretty good for me.
• This is already my second favorite round to shoot suppressed, after .22LR. Not good, since it’s very expensive stuff! I need all INGO members to buy 8.6 Blackout rifles and ammo so prices come down a bit.

After getting a few suppressors, I feel like I don’t even want to shoot without one anymore, so I may be biased. However, I think this is currently the best subsonic performer you can get in terms of the combination of quietness and damage to the target. Yes, I know some of the AR-15 thumper rounds may have heavier bullets, but I’m convinced that there is indeed something to the whole 1:3 twist rate effect. Plus this is way quieter than suppressed 450 Bushmaster subsonics. In my opinion, we have a winner!

 

[Aszerigan]

Got my first chance to shoot some suppressed subsonic 8.6 Blackout this past week and I’m a believer! I used 342 grain Gorilla “Pork Shredder” ammo out of a 12” barrel with a Q Porq Chop suppressor. Here are some of my initial, non-professional thoughts:

• For what it is, it’s amazingly quiet. I shot it right after some 300 BLK and think it may be very slightly louder or the same in terms of decibels, but it has a lower tone, so it sounds a little quieter than 300 BLK, if that makes any sense.
• This subsonic round should be very effective on any creatures you can find in Indiana (and probably way beyond)! I shot the first shot into the ground and tried to find the bullet, as they open up like a mini blender blade. Shooting into compacted clay soil, it was a small hole for maybe 1 1/2 - 2” and then opened up into an inch wide channel in the dirt. I dug down a foot or so and never found the bullet. Pretty impressive, especially with the soil density!
• I was pleasantly surprised with the accuracy. Once I got used to the gun, trigger, etc. I was able to put 3 rounds in a group about the size of a quarter from 40 yards away. I’m far from the best shooter, so that’s pretty good for me.
• This is already my second favorite round to shoot suppressed, after .22LR. Not good, since it’s very expensive stuff! I need all INGO members to buy 8.6 Blackout rifles and ammo so prices come down a bit.

After getting a few suppressors, I feel like I don’t even want to shoot without one anymore, so I may be biased. However, I think this is currently the best subsonic performer you can get in terms of the combination of quietness and damage to the target. Yes, I know some of the AR-15 thumper rounds may have heavier bullets, but I’m convinced that there is indeed something to the whole 1:3 twist rate effect. Plus this is way quieter than suppressed 450 Bushmaster subsonics. In my opinion, we have a winner!

Thankfully it wasn't a PorQ Shredder. *dum-dum-hiss*

That round has some serious punch and great potential. I don't think it's going to be a fad like people think. With SAAMI adoption and Q/Faxon making parts, barrels and full rifles, I think it'll steal some ground from 350 Legend, 45 Bushmaster and some other +32cal offerings.

Suppressed is where it really shines. It's low thump makes it pleasant to listen to and there's no *pop* like smaller calibers. It's pricey to shoot but if you reload, it can be had for well under $1 per round.

Welcome to the club @profjeremy, and save that brass !

 

[Aszerigan]

You vs the round she told you not to worry about.

 

[profjeremy]

Thankfully it wasn't a PorQ Shredder. *dum-dum-hiss*

I’m speculating, of course, but I would bet that the people who’ve had the bullets expand immediately out of the barrel “because of the twist rate” are either not using monolithic copper bullets, loading the rounds beyond bullet recommendations, or some combination thereof. Then when they blow up their suppressors, the round sucks.

 

[Aszerigan]

I’m speculating, of course, but I would bet that the people who’ve had the bullets expand immediately out of the barrel “because of the twist rate” are either not using monolithic copper bullets, loading the rounds beyond bullet recommendations, or some combination thereof. Then when they blow up their suppressors, the round sucks.

It due to shooting supersonic bullets that aren't solid copper. At 472,000 RPM, nothing is holding together that isn't solid metal.

 

[profjeremy]

 

[two70]

Thankfully it wasn't a PorQ Shredder. *dum-dum-hiss*

That round has some serious punch and great potential. I don't think it's going to be a fad like people think. With SAAMI adoption and Q/Faxon making parts, barrels and full rifles, I think it'll steal some ground from 350 Legend, 45 Bushmaster and some other +32cal offerings.

Suppressed is where it really shines. It's low thump makes it pleasant to listen to and there's no *pop* like smaller calibers. It's pricey to shoot but if you reload, it can be had for well under $1 per round.

Welcome to the club @profjeremy, and save that brass !

I doubt it will steal much ground from .350 Legend, .45 Bushmaster or similar since those cartridges are legal for deer hunting in several Midwestern states and the 8.6 would not be. I can easily see it eventually supplanting the .300 BO for suppressed usage though. Maybe sooner than later if the trend toward lighter .308 sized semi autos continues.

 

[profjeremy]

Not the most exciting or polished YouTube video, but a good overview of what the 8.6 Blackout 342 grain Gorilla bullets do in ballistic testing. @Aszerigan just so happens to load these hunting/defense subsonic rounds!

 

[Aszerigan]

Not the most exciting or polished YouTube video, but a good overview of what the 8.6 Blackout 342 grain Gorilla bullets do in ballistic testing. @Aszerigan just so happens to load these hunting/defense subsonic rounds!

Did some water testing and man, these thing dump a LOT of energy.