What is a 8.6 Creedmoor?
First off, it is now officially called the 8.6 BLK or 8.6 Blackout, dubbed such by the very creator Kevin Brittingham. Kevin, owner of Q and inventor of the .300 Blackout cartridge first came up the with idea of a .338 caliber cartridge like the .338 Federal, but better because it has a shorter 6.5 Creedmoor based case, so it could accommodate larger and longer bullets than the .338 Federal in normal magazines, which would mean it could provide for a cartridge that could be effective at both subsonic and supersonic muzzle velocities. Not only does this owe for interesting low-noise subsonic rifles, but also for short barrel, high-punch rifles and even a cartridge being able to feed in a semi-auto configuration.
Back in 2018 when Kevin initially developed the cartridge and worked with the idea, trying to get Hornady to start manufacturing the cartridge, he intended to call it the 8.6 Creedmoor, but in June 2021 when Q made the official announcement of the cartridge on their Instagram account, they dubbed it the more appropriate 8.6 BLK or 8.6 Blackout, owing to their own unique .300 Blackout, but necked up to accommodate the 8.6 caliber bullet, and also uniquely identifying it as separate from the Creedmoor sports developed cartridges like the 6.5mm Creedmoor and the 6mm Creedmoor.
The reason why Q and Hornady are only now officially bringing it to market in 2021, is mainly because of the ammo crisis that hit since early 2019, which meant that they could not even keep up with demand of current cartridge ammo, let alone start manufacturing or marketing a new cartridge.
Initially to create brass for 8.6 BLK cartridges, one could cut shorter and neck down high quality 6.5mm Creedmoor brass with a good full length sizing die and enough case lube. Thankfully though, if you are a little patient, both Q and Hornady, should have brass available soon.
Why a New Cartridge
Yes, it feels like every week someone is just necking some other cartridge up or down and “bringing out a whole new cartridge”, but this time, it is really a game-changer. The 8.6 BLK is not just an improvement on previous designs or a wildcat, it changes what was thought best for hunting cartridges and tactical military cartridges all together. It shows that large long bullets can work out of small cases, and even better, high energy effective hunt kills can be made out of short barrels, even at what would be considered long range distances for hunting.
Create Your Own
There aren’t really any large scale manufacturers making a 8.6 BLK Factory Rifle yet, however, if you jump on the waiting list now, you may be able to snag one of the early ones when they become available soon from Q and Faxon firearms, or you can even just buy a barrel conversion from them if you already have a Fix by Q.
The other manufacturers should jump on the band wagon offering 8.6 BLK chambered barrel pretty soon after Hornady starts making the brass available, and you can even have your own build on a .308 bolt face, standard-length action, by chambering a .338 / 8.6mm barrel in it once reamers become available (just remember the tight twist rate needed to make the most of this cartridge).
8.6 BLK Twist Rate
Very fast twist rates like 1:4 and even 1:3 are used for the 8.6 BLK, as this provides greater energy at supersonic velocities, and greater accuracy at subsonic velocities, thus enabling the use and stabilization of such long and large bullets out of such short barrels. The fast twist rate, also ensures good bullet expansion even at slower velocities.
8.6 BLK Ballistics
When loaded with a 210gr Barnes TTSX bullet at a conservative 2000fps from the short 16″ barrel, you still have over a 1000 ft/lb energy on target at 375 yards, although this round is not really made for such long distances. The designers also claim that the normal energy on target figure is not applicable as the incredible rotational energy of the projectile spun at such a high speed because of the 1:3″ twist rate, multiplies the energy on target, see this video to show that.
EDIT: Ballistic figures, chart and graph was updated in June 2022 to get closer to actual achieved muzzle velocity figures now that the round has been tested more, and showing that the initial muzzle velocity figures claimed by Q were a little overstated.
8.6 BLK for Hunting
Although very practical as a new do-all military cartridge, hunting is where the 8.6 BLK really shines. It redefines the general purpose hunting and utility rifle genre. Even during testing and R&D hunts, Kevin Brittingham and the guys from Q have been making waves online with their small Fix 8.6 BLK taking down everything from smaller CXP1 sized animals like a Black Backed Jackal, CXP2 sized game like deer, CXP3 sized animals like a large Kudu bull, all the way through to the very large and thick-skinned CXP4 sized African Cape Buffalo. Proving the versatility of the cartridge and rifle platform for a single, compact, do-it-all hunting rifle.
8.6 BLK Barrel Length
Because of the aim of the whole 8.6 BLK development was a compact utility / hunting rifle, it is designed to work well in short, and I mean real short barrel configurations. With Kevin doing most of the 8.6 BLK testing in a 12.5″ barrel, like can be seen in the hunting photos above, they even have a ultra-short and compact 8″ barrel version, still apparently packing more energy at 600 yards, than a .45 ACP round has at the muzzle, unbelievable or in the words of the Q-team themselves, unpossible.
8.6 BLK vs .338 Federal
Most people that first read or heard about the 8.6 BLK, quickly asked why, given the similarity or superiority (as they thought) of the already available .338 Federal cartridge. Well, the 8.6 BLK is the quieter and more efficient version of a .338 Federal, basically with a trimmed back case and improved shoulder so you can get longer heavier subsonic bullets than you can with the .338 Federal. Overall it’s a more efficient and versatile design than the .338 Federal.
Whilst the case length of the .338 Federal is 2.015”, the 8.6 BLK case is 1.685” in length, allowing the ability to run heavy subsonic loads, 280 to 360 grains or more, whilst the longer 338 Federal case will put the ogive of those long projectiles back inside the case, which will perform badly.
Although having a smaller case capacity, the 8.6 BLK offers more consistent ignition of the powder thanks to more case fill, which gives you more consistent performance, especially with those heavy subsonic loads. Another big upside due to the shorter case and cartridge length, the 8.6 BLK will feed out of .308 Winchester length magazines, allowing greater compatibility. Even the fact that the 8.6 BLK uses the same bolt face as the .308 Win, means you can change your barrel on your Fix or other current rifle and have your own 8.6 BLK.
Lastly, when looking a long bullets like the Berger 300gr Hybrid with a nose length of 0.955 inches, but the case to OAL length of the .338 Federal is only 0.785 inches, meaning that those bullets or similar cannot be reliably fed from a magazine, whereas it can in the 8.6 BLK.
2450 for 210 gr tsx is pretty fast for a 12.5″ bbl, especially in light of previously published 160 gr barnes going 2500.
Don’t get me wrong. I’m excited for numbers like that! I just want to make sure it’s not a typo, that this is a reasonable expectation.
I can’t wait for this cartridge to come out.
John Niemann says
I saw the designer quoted elsewhere that the 160 was running around 2400 and the 210 ttsx at 2000. Don’t know how he came up with 2450 for the Drop chart
THIS. It’s good for people know now that barrels are starting to show up out there that Q’s own load data gets you nowhere near what’s stated in this article. I feel this is just a hype piece that was put out to keep interest up when they were trying to get the development done on this.
I recommend this article be updated as it’s pretty non-factual at this point.
If you’re not going to buy solid copper expanding bullets and actually hunt suppressed at close range, I see zero reason for this cartridge beyond novelty.
Kevin B says
This is not a close range only cartridge. That’s just false. I have harvested animals from 9-500 yards with supers and 250 yards (so far) with subs.
Fast twist changes terminal performance with super and and subs and allows you to do things with short barrels and light weight, compact guns never really done previously.
Derek H. says
twist rate can only do so much… you still need barrel length to accomplish velocity because you don’t have time to get powder to burn fully. You may be able to harvest out to 500 yards, but, if this is a shortened .338 Federal, then it’s still lacking compared to a .300WSM which beats .338Federal at the same 500yd mark with less drop, more velocity, more energy, way less wind drift, and a faster flight time… this really seems like someone came up with a cartridge to solve a problem that didn’t really exist…
Kevin B says
Practical velocities from the 12” are about 2100-2200fps with 160-210gr. projectiles.
James Adkins says
Is there an estimated time frame to be able to purchase the 12.5 barrel to convert the AR-10 platform?
If possible, is there a way to get on the pre order list?
Gorilla ammunition is taking preorders on rifles/pistols now.
Michael Lloyd says
I’m ready to change my old AR10 and this looks like a cartridge that I’m going to love. Timing?
Earl Sobieralski says
AWSOME!!!! I have been holding out on purchasing a hunting semiauto for the best hunting and protection rifle and you have just provided the most versatile round out there for hunting. Simply Amazing. thanks v/r
Keith ross says
Can you show us these speeds chronograph old guys like me would love to see that out of short barrel thanks
Ronald Jones says
I love the 338 Federal, I don’t see how you are getting the velocity you quote out a 12.5 inch barreled 338 Savage, I’ not saying I doubt you, just don’t know how your doing it unless you are using Superformance technology which means handloaders will be disappointed.
What I really want to know is, how on Earth did you find a PH that would let you kill a Cape Buffalo with a low power 338 Federal carbine? No amount of “magic barrel twist” will make that be something that you should do.
I get it, you need it to fit in an AR mag, and the 338 caliber is great, but we really do need to think about responsible advertisement.
Kevin B says
Fast twist is using more available energy. I’ve killed 4 Cape Buffalo with 8.6blk with 10”-16” barrels. It’s efficient.
And when developing new technology, eventually, someone has to field test what the math, computers, and gel tell you.
Roscoe Lee Drake says
He did not invent 300 blackout. Research the 300 2hisper, or just read the first couple of lines on wikipedia.
Roscoe Lee Drake says
Kevin B says
They aren’t the same.
kevin gray says
210 bullet at 2450 NO, just saw the load they been using and it is a 210 grain bullet at 2000 fps , huge difference so big in fact if this turns out to be a fact I would not get one
kevin gray says
NO, this is not true , a 210 barns is only going 2000 fps with the 8.6 Blackout , which is not good, subsonic seems to the real only use for this round
Kevin B says
Fast twist, rotational velocity is the benefit and what you are missing. Makes 12” 8.6blk more effective than 16” .308win.
John ROBERTS says
Maybe a 180 gr. at 2200 fps, if your lucky. Overhyped bigtime.
Larry S. says
This is marketing is nonsense. 338 federal can be hand loaded to subsonic velocities with heavy bullets.
“More consistent powder burn” is a farce as the parent case is the same diameter as all of the .308 family.
Simply a less powerful version of 338 federal. This is 44 special compared to 44 magnum. The only advantage would be commercially produced subsonic rounds. Which is no advantage over 338 federal. 300 blackout succeeded because of the anaemic kinetic energy performance of 5.56. A .308 Winchester doesn’t have that problem, and there wasn’t a dire need to slow down a heavier round for increased penetration.
338 Federal Velocity (1st#) and energy (2nd#)compared
300 WinMag (180gr)- 2960/3502
35 Whelen (225gr)- 2600/3377
338 Fed (200gr)- 2700/3237
7mm Mag (160gr) – 2950/3091
30-06 SPFLD (180gr)- 2700/2913
308 Win (165gr) – 2700/2671
100 yards: zero
300 WinMag – 2701/2915
35 Whelen – 2351/2761
338 Fed – 2487/2746
7mm Mag – 2752/2691
30-06 SPFLD – 2512/2523
308 Win – 2501/2291
300 WinMag – 2456/2411 -3.3”
7mm Mag – 2563/2333 -3.1”
338 Fed – 2284/2316 -4.1”
35 Whelen – 2116/2238 -4.9”
30-06 SPFLD – 2332/2174 -4”
308 Win – 2310/1955 -4.1”
7mm Mag – 2381/2014 -11.5”
300 WinMag – 2224/1978 -12.3”
338 Fed – 2090/1940 -15”
30-06 SPFLD – 2160/1865 -14.5”
35 Whelen – 1895-1793 -17.3”
308 Win – 2128/1660 -14.7”
7mm Mag – 2207/1730 -26.1”
338 Fed- 1905/1612 -33.6”
300WinMag – 2005/1607 -28.4”
30-06 SPFLD – 1995/1591 -32.4”
35 Whelen – 1690/1428 -39.9”
308 Win – 1954/1399 -32.9”
Kevin B says
No. Calculate 1:3 twist rotational energy. And you can’t get subsonic accuracy with slow twist.
Kevin Niedzwiedz says
What reliable expanding bullet is there in the market for the 0.338?
Lehigh don’t make any 0.338 subsonic specific anymore..
Kevin B says
Hornady subx and gmx, Barnes, Discreet, Makers, etc. Most existing bonded and solids work perfectly.
Coconut Empire says
What about hard cast/HTC coated projos?
338 Federal has already suffered from the lack of .338 Projectiles that expand reliably at its velocities. How is this round, which is even slower going to magically do better?
Kevin B says
Fast twist. Fits in mag.
Why is this better than a 450 bushmaster? The 450 fits in an AR-15 platform and actually can fire a 200 grain bullet at 2500 fps. I get that ballistic coefficient is probably really good for the 8.6, but so good that starting out 400 fps slower doesn’t even them out? Is it the crazy twist rate? I mean what does it do that an AR-15 big bore cant, why should I buy one? Both bullets are going to drop like rocks at distance.
Yeah and the 300BLK was poised as the greatest Hog Hunting round ever in all the Gun Magazines.
You couldn’t convince the fanboys and casuals otherwise that they bought a .30 carbine.
We see how that turned out. 300BLK sux for hunting outside 75yds.
I don’t see how this new 8.6 trumps a .308 other than its ability to be a little more effective when going sub sonic. You can run a .308 with 220gr match kings or game kings at 1000fps and do fine. Switch to match ammo and hammer out to 800 yds or better.
It sure doesn’t beat 308 on being versatile and ammo availability.
But more power to him if he can sell a new system. Marketing genius.
Kevin B says
Barrel change only. Supers and subs. Full mag capacity. Reliable. Distance. Accuracy.
What barrel length is optimal shooting suppressed in the 8.6 cartridge? I would think a 16” would be quieter, but this round appears so unconventional I don’t know what think.
Robin Patty says
I definitely want one. I already have a couple of their guns, a Honey Badger and a Mini Fix both in .300 Blackout. A couple of decades ago I used to shoot a .300 Whisper a good deal and really liked it, so why not. JD Jones has come up with some great cartridges over the years but he never really, in my opinion, carried them through to their place in history like Q has done, and now that they have the 8.6mm Blackout it looks like I’m forced to spend more money. 😎
1:3 or 1:4″ twist? I asked this on the Firearms Blog and I was told to look at the video linked above. The ‘super spinny’ bullet hits centre of the block where its expansion can be fully seen and as such its expansion is mostly undisturbed. The normal spin bullet hits almost the bottom of the block, where its expansion cannot be fully seen and its expansion is highly disturbed by the table. This has got to be one of the poorest examples of a difference I seen in a long time. Plus, these are very light for calibre 140 gr projectiles, so these do not exactly sound normal
As to a required twist rate for stability, with a 1:10 twist, at +69F (+21C) 1,070 fps (326 m/s) a 300 grain (19.4 g) Sierra Match King is just ‘gyroscopically’ stabilised, with a stability factor of slightly greater than 1.4. A 1:9 twist gives more than adequate stabilisation of about 1.76 at the same muzzle velocity. Even with 300 gr all copper bullets like the Cutting Edge Lazer, this can be adequately gyroscopically stabilised at subsonic velocity with a 1:8 twist, with a 1:7 being better.
I can see that this higher spin may be advantageous in that the extra spin opens up and breaks off the petals of mono-metal subsonic projectiles? But over gyroscopically-stabilising projectiles can lead to no end of accuracy problems. This such as it the projectile being gyroscopically stable, but dynamically unstable, and that the projectile can no longer able rotate around its centre of gravity to its nose follows the ballistic trajectory, i.e., the tractability problem. This is even more problematic when firing anything at supersonic velocities.
As such I’d like to see the downrange accuracy of these over-stabilised bullets and a proper comparisons of projectiles hitting gel blocks, as at present this all looks and sounds like marketing rubbish too me. Personally, I’d much rather have a correctly technically (ballistically) designed rifle with a barrel that has twist rate that adequately stabilises the bullet and does not potentially cause accuracy problems. Though the daft 1:3/1:4 twist rate may give a bit of an improvement in the terminal ballistics of mono-metal projectiles, I’d rather something that can hit a target at all ranges. It would be far better to simply use (develop) better-designed mono-metal or thin-jacketed lead alloy core bullets that expand at low velocity and normal spin rates than use this over-stabilisation method to supposedly improve terminal ballistics.
Nate Revo says
Best answer yet. I purchased the AR-10 barrel for a Palmetto State Armory PA65 I have in my inventory. After working through many loads, and dealing with brass issues (turning necks ) I’ve come to the conclusion that this is the most complicated cartridge ever designed. What other cartridge has to match ammo to the barrel length?
Anatoliy Kanevsky says
I’m new in this game with 8.6 blk and trying to find out how much powder of 1680 accurate I shout try with 300gr sierra bullet and 285 gr bullet from gorilla ammunition? Any data would be helpful. Thank you all for help.