Reader Erik writes:

I’ve been reading many articles re. defensive rifles/ammo and it seems I’ve noticed your fondness for the .300 BLK round.  I am impressed as well but the overall lack of its use and the increased cost/round concern me.  I know that round for round 6.8 SPC ammo is about the same right now, but given the increased popularity of the 6.8 with many military agencies, I am betting that over time the round will become more available (just like the 5.56 is now) and will become less expensive. Would appreciate your thoughts on this.

I get this a lot, actually. And its a valid question — what makes 300 BLK so much better than the other calibers available for the AR platform? And is it actually better? So here’s the truth…

It depends on what you want to do.

I’m going to break this into three categories, encompassing everything a shooter should consider when choosing a caliber: performance, compatibility and availability.

PERFORMANCE

The 6.8 SPC and 300 BLK cartridges were designed for two very different jobs. 6.8 SPC was designed to be a longer range cartridge, while 300 BLK was designed to be a shorter range cartridge that worked well with a silencer. I interviewed Kevin Brittingham, founder of AAC (and godfather of the 300 BLK cartridge) and he had this to say about his round:

These were our original requirements for this caliber: Muzzle energy has to equal or exceed the AK-47. .30 Caliber projectile. Use unmodified 30 round magazines to full capacity. Use unmodified AR-15/M-16/M-4 bolt. Gas impingement system. Shoot super and subsonic. And one thing that was nice, but was not a ‘deal killer’, was non-adjustable gas system. Cycle all four ways – subsonic suppressed and unsuppressed, and supersonic suppressed and unsuppressed.

[…]

It’s not one of the 6.5 or 6.8 or whatever is the flavor of the month where it’s a do-all, kick-ass… From a military standpoint, here is the advantage (which we discussed earlier): all we need is to change the barrel and get the ammo. Non-adjustable gas system… And that’s a huge thing. Nobody works with silencers more than us. Every time I’m working with a company on something, whether it’s LWRC or Colt or FN, whatever it is, if it’s got an adjustable gas system we get halfway through the test and we’re like “holy shit, we didn’t adjust the gas system.” It’s not something that’s really intuitive, you gotta think about having a suppressed system or unsuppressed. If you can get away with a non-adjustable it’s always best. And we’re able to achieve that, and it’s because we did the whole gun; we did the ammo and the silencer so it all works together.

So, 300 BLK was designed to fill a specific role. It was designed to be a big, heavy round that can be quickly changed from subsonic to supersonic and suppressed easily.

6.8 SPC, on the other hand, was never intended to be quiet. The relatively small projectile was designed to add a little more mass to the round while maintaining that zippy velocity that gives 5.56 ammo its punch. And thanks to that extra velocity, the 6.8 SPC does indeed perform better at longer distances.

Out at 500 yards, 300 BLK drops a whole extra 30 inches compared to 6.8. But to 200 yards, the difference is less than two inches.

That higher velocity also means that the 6.8 cartridge has a higher muzzle energy than the 300 BLK, clocking in at about 1,694 foot pounds for the 115gr variant to 300 BLK’s 1,360 for their 125gr offering. And the 6.8 SPC’s performance only improves with added weight. (By the way, 5.56 NATO 55gr comes in at 1,188 foot pounds.)

So, in short, if you really want the most muzzle energy and long distance performance then 6.8 is the way to go. Actually .338 LM is the way to go, but that won’t fit into an AR-15 magazine.

COMPATIBILITY

To me, the entire point of having a funky caliber in the AR-15 platform is to be able to switch quickly and seamlessly from one caliber to the other. I should be able to swap uppers and be good to go. And, in general, that’s possible with both calibers. But one caliber really does it better.

The 6.8 SPC cartridge is designed from the .30 Remington cartridge, meaning that it will not work with a standard AR-15 bolt. You need a slightly larger bolt, which means less material on the bolt face to contain the force of the escaping gasses and a higher probability of failure (less material + higher muzzle energy…). And when it fails, you’ll need one of your special snowflake bolts instead of any old standard AR-15 bolt.

Speaking of special snowflake parts, while the 6.8 SPC will fit in an AR-15 magazine, its actually too fat to work at full capacity. Most manufacturers appear to warn users to only load five or six rounds to avoid bulging the magazine. Magpul is coming out with a new magazine specifically designed for 6.8 soon, but the rumors are that it will only work in LWRC’s special purpose-built 6.8 lower receiver and not standard ARs.

The headache doesn’t stop there, though. There are, by my count, four incarnations of the 6.8 caliber. One is the SAAMI spec, which is a lower pressure load. Then there’s SPC II and 6.8×43, both of which have different chamber pressure ratings. And finally there’s Noveske’s Mod1 design, which apparently allows the highest pressures and best performance — but its proprietary, and not cheap. In short, you need to double check that you’re buying the caliber you want before you drop the coin on that new upper, and ensure that you’re getting the right ammo.

300 Blackout is much simpler. There is only one flavor, which is an open and freely available SAAMI spec that is already rated to a higher chamber pressure than its wildcat predecessor (the 300 Whisper). Which means that if you get a 300 BLK barrel from any manufacturer you can rest assured that its going to take any 300 BLK ammo you throw at it and more.

300 BLK also removes a lot of the equipment headaches. Since it is made directly from 5.56 brass and was designed specifically to work in standard AR-15 magazines, it works flawlessly with standard AR-15 bolts and magazines. There are no issues with feeding, no issues with magazine capacity, and spare parts are abundant since the only real difference is the barrel.

So, if you’re looking for a simple drop-in change for your AR-15 that works with all of your existing gear and spare parts then 300 BLK is the way to go.

AVAILABILITY

Having a gun chambered in a kickass caliber doesn’t matter if you can’t find any ammo for that gun. And, right now, 6.8 SPC is winning.

6.8 SPC is just about everywhere — the only place I still can’t find it is Wal Mart. Its been about a decade since the first 6.8 rounds started appearing, and so just about every manufacturer has a load available and ammo in stock. And, thanks to the community of shooters using 6.8 SPC already, there’s no doubt that this round will continue to be available in the future as well.

300 BLK is the new kid on the block. It hasn’t been adopted en masse by military or law enforcement just yet, so there’s no milsurp loads available. But while the “professionals” might not have adopted it, I’ve seen more and more hunters adopting the round as a way to quickly change from their 5.56 M4gery to their hunting rifle. Especially down here in Texas where hog hunting is huge, the ability to switch between subsonic and supersonic and suppress the ammunition effectively is a HUGE plus. That use case has led to a huge demand for guns in the new caliber, and these days just about every manufacturer makes a gun in 300 BLK.

While the growing number of 300 BLK owners bodes well for commercially available loads, one of the best things about 300 BLK is that it will always be available as long as there’s new 5.56 ammo being made. Well, for handloaders at least. Since the 300 BLK round can be made directly from 5.56 brass you will always be able to make ammo for your gun even if the manufacturers stop making it. 6.8 SPC, on the other hand, uses the obsolete 30 Remington cartridge that hasn’t been produced commercially en masse in decades. So if manufacturers stop making 6.8 SPC for some reason, unless you have a stockpile of old brass you’re kinda screwed.

In the end, though, its a tie for availability. 6.8 SPC is already widely available, and 300 BLK has the backing of one of the largest ammunition manufacturers in the world and the largest firearms company (Freedom Group) known to man. Putting aside my conspiracy theory about 300 BLK being Freedom Group’s Apple-like walled garden attempt, that’s a lot of resources being thrown at making 300 BLK a viable caliber for the average shooter.

SUMMARY

Like I said at the beginning, it all depends on what you want to do.

If all you’re looking at is muzzle energy and long distance performance, then 6.8 SPC is the clear winner. Its a field tested and battle proven cartridge with a huge following that can put animals down at longer distances than 5.56 NATO. And if you’re comfortable with the slightly more complex world of parts and ammunition, then go for it.

But if you’re looking for something for hitting living animals up to 200 yards away, does better than 5.56, uses all your existing gear, can swap easily from supersonic to subsonic and is easily suppressed, then 300 BLK is the winner. It may not be a great long distance round, but the compatibility with existing gear really was the feature that sealed the deal for me.

I like 300 BLK. But then again, you knew that already. And really, if I wanted something harder hitting or for longer distances, 7.62 NATO would be my choice.

[Email your firearms-related questions to “Ask Foghorn” via [email protected]. Click here to browse previous posts]

RELATED ARTICLESMORE FROM AUTHOR

77 COMMENTS

  1. The overwhelming response to this round has me scratching my head where the 6 x 45 is concerned. I still don’t understand why that round hasn’t taken off the same way.

    • I *LOVE* 6×45! It is my go-to for whitetail hunting. Slightly necked up 5.56, the 6mm round has a great BC, is actually softer shooting than 5.56 (if that were actually possible) and I can get a Sierra 85gr BTHP GameKing going along at 2900 fps. Like Nick was saying, when hunting season hits, I pop off the 5.56 upper, pop the 6×45 upper on, verify the zero on the 3×9 scope that’s mounted to that upper and I’m good to go. Yeah, you have to reload, but like .300 AAC, brass is always available and 6mm bullets are cheap. It’s a great round. I’m actually building a .300 AAC right now because I plan on letting my 9yo daughter use the 6×45 for next year’s season and I’ll use the .300 AAC.

    • if i want to reach out and touch some thing ill grab my 30 year old Remington 270 bolt gun with it trusty old Leopold VX3 scope
      if i want to shoot some hogs my 300 AAC is the way to go with my TruGlo 2-Color Gobble-Dot site
      and for plinking my AR15 5.56 is about the cheapest way to go

  2. And really, if I wanted something harder hitting or for longer distances, 7.62 NATO would be my choice.

    That pretty much nailed it right there.

    • +1. If I can’t get it at my local merchant of death or the nearest Walmart, at a reasonable price, it’s not going in my stash. I’m not an early adopter. I don’t like paying a premium for something that “fills a gap” (like .45 GAP). “Boutique” ammo, like all things boutique, are for the silly fashionistas. I’ll gladly make due with whatever is at hand.

    • I love this!
      “The 6.8 SPC and 300 BLK cartridges were designed for two very different jobs. 6.8 SPC was designed to be a longer range cartridge, while 300 BLK was designed to be a shorter range cartridge” wait wait wait
      Isn’t this the exact same rehashed line you get from 68 fans when you show them a ballistic table comparing 6.8 vs 6.5?
      The terminal effectiveness gap between the two is negligible at most. So why not go with the round that gives you drastically more range? If I need a short weapon with a rifle power round I’ll get an ak pistol. It just seems more practical to me. Less expensive to shoot and easier to find too.

    • @ Nick Leghorn: “I like 300 BLK. But then again, you knew that already. And really, if I wanted something harder hitting or for longer distances, 7.62 NATO would be my choice.”
      =======
      I built a .22LR Upper, AR-15 (5.56 x 45 NATO) Upper and a .300 Blackout (7.62 x 35 NATO, yes!) Upper – all “lefties”, all paired to a super-tricked out AR (15) Lower ….. and I “topped the tank” with an Aero Precision M5 (AR-10 or AR-308) system (.308 / 7.62 x 51 NATO).

      In order, they go poop, pop!, bang!!! …. and KA-BOOM!!!!!!!!!!!!

      “Harder hitting” indeed!

  3. Excellent article. I would add that there are more energetic and ballisticly efficient loads than the original 6.8 115 OTM load. Namely the Silver State Armory 140 grain Berger VLD at 2400+ FPS and 1800 + FPE from a 16″ barrel. I’ve read reports that actually velocities in a 16″ barrel are around 2450 FPS, but I cannot confirm this because I don’t have a chronograph.

    The 300 has some very cool things going for it, and has added a very cool load using the 130 grain barrier penetrating round based upon the 7.62 x 51 Federal / ATK bullet (it’s either the SOST MK 316 or 319).

    And I still want to know where I can get the custom Pmag that you have in the picture above. It would look dead sexy in my Ruger SR-556…

  4. I definitely agree with Foghorn’s analyses.

    It’s good to remember that .300BLK was designed to replace the MP5 and MP5SD. It makes for a great round when paired with a suppressed SBR. Perfect for home defense, especially with children/other things whose hearing you wish to protect.

    • 300 blk works great in SBR with ultra short barrels… 8″ no problem.. 6.8 spc needs 11.5″+ barrels for optimum effect and range… and does best with a 12.5 or longer barrel.

      4.5 inches is a big difference when you consider a suppressed 300 BLk CAN be as long as a unsupppressed 6.8 spc.

      • Welllllllll…… the 6.8mm SPC was designed with CQB SBRs in mind, e.g., the LWRC Personal Security Detail with the 8.5″ barrel. Great terminal ballistics >300 yds.
        http://www.defensereview.com/68x43mm-spc-cartridge-for-urban-warfare-cqb-and-short-to-medium-range-sniping/

        The article has good analysis, but a bit .300 BLK leaning. The Barrett Rec7 mags work in all the 6.8mm mil-spec lowers (e.g., LWRC M6 series). But yes, there’s a PMAG for the Six8 series. And I’ve never even heard of a Noveske 6.8mm cartridge before now, much less seen it ever being for sale… there’s pretty much only 1 SPC cartridge now (just look on AmmoSeek, Midway, etc.)

    • One of the big drawbacks of the 6.5 Grendel (as an example) is non 5.56 b.c.g.s and magazines. As a Grendel owner, the bolt doesn’t bother me too much since it’s a one time purchase (although I’m all about saving $200), but not being able to use factory 5.56 AR mags sucks.

    • Something or someone that is out of the norm and requires/demands special treatment thereby is referred to as “being a special snowflake”.

  6. Nick, did you buy off the shelf for your 300 BLK M4gery or did you do a build? I know you’ve hunted wild hogs with it, and have you used it for any other huntin’?

    This caliber has intrigued me, because I’ve been on the fence with the 6.8 (meaning spending cashish to buy one) vs. the 300 BLK. Like the interoperability of the weapon system.

    • I haven’t actually successfully shot anything with it yet, though.

      I plan on using it for general hunting this year, everything from deer to hogs. Leupold makes a scope calibrated for 300 BLK with range marking on it for supersonic and subsonic, and I’m planning on putting it through its paces this year.

      • Thanks. Looking forward to a write up on your hunting escapades with Mr. Tyler Kee?

        Plus playing with that new toy of yours, the scope should be fun…

  7. Nick, thanks for your analysis. I’m building an AR and one of my first big upgrades is going to be a larger caliber upper. I was thinking 6.8 until I heard about .300BLK from you on TTAG. I’ve been fascinated with it much more than any round I’ve ever come across, have have never fired either. This article better articulates which round is more suitable for my needs. Thank you.

  8. The article yesterday where someone was up in arms about .300BLK being terrible for hunting actually sold me on the round. You mean to tell me that with a single weapon I can have the equivalent of a .45ACP submachine gun (with subsonic) AND a semi-auto .30-30 (with supersonic)? And all on the exact same platform I’m used to? Yes please.

    • Which raises a related question–this whole thing about hunting with silencers in Texas. Are you trying to tell us now, unlike yesterday, that an equivalent to a 45 acp is sufficient for hunting hogs? I don’t know about Texas, but in these parts (northern California) a good sized boar will run 350 lbs–not something I would want to anger with a 45, even if the fmj round is supposed to be able to take down a horse. And you can’t hunt in this state with 223, even for our 100 lb deer.
      Now I am sure some disagree, but I don’t think the 223 is good for hunting anything larger than a varmit. And if the 200 gr subsonic 300blk is less effective than even that….how can it be ethical to hunt with it?

      • If I recall, Nick was saying the supersonic round (125gr) mimics a .30-30 and is suitable for some hunting, but the subsonic 200gr round mimics .45 and was a terrible idea.

  9. An additional issue in the 6.8 is that many of the barrels available are obviously using the same blanks as intended for .270 Winchesters – they have a 1-in-10 twist.

    This is too fast for the lighter bullets the 6.8 SPC uses. The lightest pills one typically sees in the .270 Win are the 110gr varmint pills (they make coyotes look like they scarfed down a frag grenade). Most of the time, tho, .270’s are pushing pills from 130 to 150gr, and for the latter, the 1-in-10 is pretty nice.

    For the lighter 6.8 SPC loads (eg, 75 to 85gr), however, it would be much better to back off the twist to 1-in-11 or 1-in-12. If you could split the difference, you’d be able to cover the whole spectrum of .277 pills being used on the 6.8.

    • It’s pretty rare to find 1:10s in new manufacture. Even Stag, who was rather famously stubborn about the twist, sells 1:11 barrels now. A 1:12 isn’t a good idea with the shift to heavier bullets for the cartridge.

  10. For me personally, I am hesitant to go with the latest and greatest in caliber. To some degree, I believe it is the gun and ammo manufacturers wanting to sell more guns and ammo. More power to them if that is true. I prefer to stick with tride and true calibers – for hunting – 30-06 or .308 (Big Game); Varmints and prairie dogs – .223, .17 HMR or .22lr. Yes, I know the .17 HMR has not been around for very long considering cartridge history, and it did take me awhile to jump on that bandwagon.

    If you want the latest and greatest, that is just fine. Of the calibers that I listed, there is nothing you can’t hunt or go after with, and it would get the job done.

  12. Um… nobody in the 6.8 community actually uses 5.56 mags. I’m not sure if you intended it to sound like a 6.8 can’t load more than 5-6 rounds, but that’s just for people who don’t want to buy a 6.8 mag. Granted, your point is about ability to use ubiquitous 5.56 equipment, but nevertheless. In case no one else mentions it, you can get 25-rounders, and there’s a rumor about a drum mag coming out soon…

    • Correct. I can get about 5 6.8mm rounds in a 5.56mm Lancer mag before it starts to split. The Barrett 30 rounders are the way to go.

  13. Where 300blk truly shines is it is a fantastically versatile round, few other rounds come close to the versatility of 300blk on the AR platform.

    300blk is also pretty much future-proofed. AAC / Freedom group could go bankrupt tomorrow and it would matter naught for the availability of 300blk. As long as .223/5.56 brass and 308 projectiles are available, 300blk will survive.

  14. I don’t know if anyone is still following this article, but does anyone have opinions on how the 6.5 Grendell (might be spelled wrong) pairs up against the 6.8 SPC as well as .300 BLK? I haven’t heard too much about the 6.5 but what I have heard seems pretty good. Not considering issues of availability, what are some ideas about this round?

  15. Snowflake bolts? Being in the industry I have never heard of a snowflake bolt so where did you get you snowflake bolts Foghorn? Re bolts being weaker and muzzle energy the cause. It should actually be the “bolt thrust” that would cause the bolt to have a higher failure rate but there doesn’t seem to be any reports of bolt failure with the 6.8 if you look around the forums. Federal is now loading 6.8 ammo. I believe Federal-ATK is quite a bit larger than Remington.
    The truth about guns huh?

  16. Snowflake? Really? 6.8 bolts are not thinner or weaker than 5.56 bolts and are readily available. You clearly enjoy your 300BO. I’m not convinced you know anything at all about the 6.8 in its present form. I laughed when I saw your bullet drop graph. While it makes sense to zero a 300BO at 100 yards, 225 is best for the 6.8. Also, I’ve never known anyone to just screw on a new barrel to an existing upper/bolt/carrier as these parts wear together. And you’d want your gunsmith to check your headspacing. The AR weapon system modularity is best utilized by swapping out full uppers. I think you know this.

    6.8 mags are plentiful. .277 bullets are more varied and plentiful than .308 and the cost per 100 is approximately the same as for 50 .308 bullets. Reloading powder options are wide open for 6.8 which allows me to shoot 120gn Hornady SSTs at 2650 fps, swap mags and shoot surprisingly accurate reversed 160gn BTSP subsonic rounds at 1050fps (yes, they do cycle the bolt and do not keyhole at 100 yds) all out of a 16 inch barrel.

    The 6.8×43 and 300BO are both fun and each has its fans. Let’s not murk the decision-making process for those choosing their next rifle with needless hyperbole, okay? Besides, everyone knows the REAL fun AR round is the wildcat based off the 6.8×43 – a 30 cal round in a reformed 6.8 case called the 30 HRT.

  17. Lets cut to the heart of the matter. The only logical reason to own the .300 BLK is if you have a suppressor and want to go subsonic.

    I strongly suspect any success the round currently enjoys speaks more to the popularity of PMAGs than any real world ballistic advantage.

    • Personally, I would love a suppressed 30BLK SBR with supersonic ammo. That sounds like the perfect home defense gun to me. A little sonic crack? Yeah, but greatly increased power.

      Too bad I live in CA…
      For the moment.

    • Or you have need for a short barrel application. The 300 BLK has the same performance out of a 9″ barrel as the .223 does a 16″ barrel.

  18. I want to see some testing with the 6.8 and the 26 inch long barrel rifle. Especially the new 140 grain and the hornady 120 grain, oh, and I want it long distance too!

  19. One comparison to do that is glaring between the 300 blk and the 6.8 is in minimum energy at distance
    The best bullet I could find for the 300 blk drops below 1000 ftlbs at 128 yards

    The 6.8 bullet I hunt with drops below 1000 ft lbs at 275 yards (120g Hornady SST)
    Thats over DOUBLE the range!
    1000 ft lbs is a rule of thumb for many for hunting mid sized animals

    Also some of the benefits of swapping barrels and bolts is a moot point because almost everyone buys a dedicated upper, and nobody I have seen swaps barrels back and forth …….. They have dedicated 223 uppers

  20. Lastly the mags are being dedicated as well, because of published kabooms because people put the wrong mags in their weapon.

    Both calibers have their benefits but to me it isnt close……..6.8 by a mile (or at least double)

    • I’m planning on coloring the portion of my mags that are covered by the magwell. (I’ve been an FAL guy for years, now I’ve been drawn in to use the AR, finally).

      I’ll use red (power!) for 6.8, blue (NATO) for 5.56/.223 and white (emphasizing black of the mag) for .300 BLK. If I ever get into 6.5 Grendel, I’ll use green, for the monster from Beowulf. 😀

  21. 1.) My upper is an LMT MRP. For me, a barrel-ONLY swap makes a lot more sense than to some others.

    2.) this trend amongst you guys (the readers, not the writers) to constantly spout “Stop liking what i dont like!” is really aggravating. It really makes me want to avoid the comment section.

    3.) 300BLK and 6.8 should probably never be compared. nor should 6.8 and 6.5 Grendel. 300BLK is a direct replacement for 5.56 and has essentially rendered it useless, but 6.8 and 6.5 are both better. different class, but different cost.

    4.) where did this “300BLK is only good subsonic with a suppressor” line come from? It has more energy than 5.56, is THAT only good suppressed?

    5.) I know it’s tiny, but It’s nice that 300BLK can use all the muzzle devices built for 7.62×51. 🙂

    I think that the fact that Leupold is making the many of their optics, like the VCOG, for only 5.56, 7.62×51, and 300 Blackout, and also that ALMOST every AR maker has 300BLK in their line means it’s pretty close to here to stay. In a relatively short time on market it’s taken a large percentage of the market-share.

  22. Re: 300 BLK ammunition. The “well dried up” after the horrible Newtown CT shooting! That was pretty much a “water-shed” moment for legitimate, law-abiding firearm owners *and* the 2nd Amendment. And – for months – ALL calibers.

    Haven’t seen a single round of retail 300 BLK since then – and it’s mid-November 2013 right now. Still can’t find CCI .22 LR “mini Mags” ……..

    But my 300 BLK build isn’t something I regret since there should be 5.56 brass until the end of time – and every possible variant of 7.62mm bullets imaginable. Add in Hodgdon H110 powder and reloading apoears to be my next mountain to climb.

    Have taken 2 wild boar with my “Blackie” and they were both one-shot, “Texas 2-steppers”; the rounds hit the target and they both took just a couple of lurch-steps and simply dropped. Both times, the guide said it looked like they’d been struck by lightning …….. Rounds were commercial with a Barnes Vor-TX bullet and there was no exit wound. One oinker was only out ~ 50m; other was a big boy out about 80-85m.

  23. good info, i cant stand when someone uses the term m4gery…..an m4 is an m4, whether its auto or not, it may not be a m4a1, but its a m4, noone calls the semi auto thompsons i see ppl with all the time thompson4gerys or 1911s 19114gerys….come on

  24. Nice write up, I have always wondered what the differences of these two rounds were and I can now agree that the .300 AAC Blackout definitely has a role to play in hog hunting and CQB. Other than that 7.62×51 for anything passed 250 yards. I like the 5.56×45 because its accurate and cheap and that’s it.

  27. I like the 6.8. Load the usually weights but have shot 130 gr @ 2300fps from a 16″bl. Working with 150 SP for subsonic loads.
    See a lot of 300 BLKs for sale.

  28. Wow, can you be anymore of a 300 fanboy, you need to do some research about the 6.8 before you write, your article reads like the Obama care law. Let’s talk about the truth the next time you write something sport.

    • I never have had a problem with my 6.8s., RRA, Stag, CMMG system, AR performance. Piston and/or direct gas impingement systems. Bolt Problems? No; Twist problems? No; Magazine problems? No; Small and Large primer problems? No. I use a number of mags and they are made of carbon steel or stainless steel. Try PRI, C Products and Barrett,

      I would not call a 6.8 a long range cartridge, but a medium range cartridge. Shooting out to 400 yards is not a problem to hit a 12″ plate any day or weather conditions. Generally shoot 110 and 115 grain bullets. If you want a 300BLK, try a 140 or 150 SP bullet in a 6.8.

      Great debate!

      • Oh, Bought some ATK-Federal Fusion 115 gr @ 2450fps, 16″ Bl from WalMart. I believe it cost $23. Not exactly sure of the velocity but remember it was lower than my usual 2600fps.

  29. The 6×45 can be loaded with 80 to 90gr to nato pressures and produce flatter trajectory and more energy and trauma on target than any other 5.56 derived caliber. AA2230, benchmark and H4895, W748, R15 and varget are good performance depending on bullet weight and barrel.
    80gr can be pumped to 3000fps at nato pressures that both the Nato cases and mil spec bolts are designed for.
    The AK and specially the whisper/blackout do not come anywhere near.
    But even the EK round for reloaders can move the 150gr bullets quite decently. The blackou doesn’t have enough case capacity for doing that.
    Look it up. The editors on this magazine should also look it up before publishing the article.

  30. I hate to break some hearts and egos, but 300 BLK is pretty low on the scale of rifle use. It is good for subsonic work, but that is it. 6.8 and 6.5 kick its azz all over on SD, power, velocity, range. Even the AK’s 7.62x39mm kicks the hell out of the 300 BLK. 300 BLK was what Remington failed to do and market the 6.8 SPC and 30 Rem AR. If you reload, it is nothing to brag about. I have owned 300 BLK, 6.8 SPC, AR10 308 Win and the 6.8 SPC is the best out of the lot. If you really want stopping power at the same 200yd and under range- buy a 458 SOCOM. That is the Mack Daddy of stopping power for hogs / game and it has way better bullet selection. I shoot one of those too. 300 BLK was a huge marketing strategy by Remington because they realized they failed earlier and have idiots working corporate level and not hunters / shooters and it shows by their stupid advertising corporate suit type non shooters. If you really want stopping power, 458 SOCOM or 450 Bushmaster – either one shame the 300 BLK. For regular deer hunting / hog work 115 Federal Fusion Bonded 6.8 SPC works better- velocity and wound cavity than any 300 BLK ever will.

  31. Also at $20 for 20 rounds the 450 Bushmaster or 6.8 SPC are more cost effective at being accurate and better wound cavity in game. If you reload, it even gets better. I can’t believe people hype the 300 BLK like it was never the 300 Whisper before Silvers got a hold of it for Remington. 6.8, 6.5, 450, 458 all are better hunting calibers than the 300 BLK at supersonic levels. Subsonic- 300 BLK with 220gr is a great pest control option. Problem is…. 338 Spectre is better and I own one of those as well… ha

  32. The amount of asshurt in the comments is mind-boggling. Jesus, boys, you’d think he was criticizing the size of your manhoods.

    This is ‘Murica… get both.

  34. Just bought a 300 blackout upper, so watch what you say because you are talking about family now!!! I really wanted a 308 AR-10 or a Ruger Mini-30, but somehow got side tracked with this whole 300 blkout thing. I guess the 308 will have to wait a little longer now that I need to stock up on 300 blkout ammo, dies, scope, etc, …

  35. Whether you’re for blackout or against blackout, it all about shot placement no matter what caliber you use I just recently killed at 325 pound hog with a 300 blackout using a 150 grain bullet With one shot I dropped him while he was running And I was only 50 yards away

  36. The .308/7.62 and the .223/5.56 have no fewer than 24 combined chambers. Far more than 6.8, which Remmington dropped the ball on.

  37. 6.8 guys are funny, instead of focusing on how to make their cartridge better they go out of their way to post and try to downgrade other competing cartridges. Having shot and owned both 300 blk and 6.8 spc, I like them both for separate reasons.

    I first owned the 6.8 spc as I was looking for a cartridge that I could shoot at greater distances than my standard 223/556 with more energy to be able to hunt medium sized game with(deer, boar, etc). The round was great but due to the limited availability and higher ammo cost after I found an ammo combo I liked for it and dialed it in I did not shoot it often, only brought it out to show friends a different cartridge really. During this time I had finished my ar308 build which although is a little heavier, pretty much made the 6.8 obsolete for me so I sold the upper.

    I purchased the 300 blk later and really liked a few things about it. All of the components were the same as my 223/556 aside from the barrel, awesome. I could shoot super and subsonic rounds both suppressed and non-suppressed, awesome. I could convert 223/556 brass into 300 blk extremely easily and load it with 30 cal bullets which I already had piles of for my 308. I especially loved this fact during the great ammo and gun component shortage of 2013, which I am sure everyone remembers. During those dark days I was able to continue firing my 300 blk due to the availability of ammo components I had available.

    I will say that with current load workups and advanced/plentiful light .30 cal bullet options out now the 300 blk can sufficiently take medium sized game up to 300 yards plus but 0-200 yards would be optimal similar to other ar-15 type cartridges. 110 vmax, 110 vor-tx, 125 nosler bt, 125 sst, just to same a few.

    IMO, if you are looking at a longer range/higher energy ar-15 sized receiver type round, I’d look into the 6.5 grendel. I have not owned one of these but I have shot a friends and it is a real tac driver. It was much easier obtaining sub 1/2 minute moa grounds with this than it was with my old 6.8 spc. The 6.5 cartridge is also superior ballistics wise and support is increasing. Look at what competitive long range shooters use, if it’s not a 6mm it’s going to be a 6.5 variant.

    Whatever option you go with you should have the tools available to maximize the weapons system you choose. I would talk to the people that actually own each cartridge in person to see what they like and dislike on top of the research you do. If you have the chance try out each system and see what you like, having options is never a bad thing when you are able to find the right system for you.

  38. i was reading all the comments on here coz i wanted to learn more about 6.8 6.5 and 300blkout and thnks to everyones input i learned new things, but i jus always hav used my mosin nagant rifle for hunting coz it wuz cheap and ammo is cheap.

  39. Its true almost everyone uses a complete upper the advantage of the 300 blk is you don’t have to keep extra bolts and magazines. The problem is if you don’t reload or don’t want to buy a 600 dollar progressive press(I couldn’t imagine cutting and forming brass then loading one at a time is very time would be much fun for a semi auto rifle) you are stuck paying a good bit for ammo. Then comes the real kicker the 300 blk just isn’t a great medium game caliber. If it was in a bolt action people wouldn’t even consider it, its no were near a 30-30 which shoots a 160 grain bullet faster than the 300 blk shoots a 120. I know people won’t like this but its really a 150 yards and in cartridge same as the 223. If you are going to handload and want a deer slayer in the ar 15 the 6.8, 30 ar , 6.5 grendel, and wssm chamberings give you a lot more range and knockdown power. The big bores 458, 450 bushmaster and 50B all add increased versatility(ability to hunt larger animals) and just as much range.
    Don’t get me wrong the 300 blk is a nice round on 2 leg critters with a increase in knockdown and barrier penetration over 223, its just not as good a hunting round as people are making it out to be.

  41. I really bought into the 300 Blackout. After testing, repeatedly, and here I mean over a year’s time, every factory brand and load I could get my hands on and in three different barrel lengths, 8″, 10″, 16″ from three different manufacturers, and shot both suppressed and unsuppressed, the average groups I get, is about 2-3 inches at 50 yards.

    This is not unique to me. A guy brought his bolt 300 BO to the range (16″) and he got similar results. It does seem that with carefully developed handloads the 300 BO may be more accurate. Now I’ve began seeing more and more accuracy issues from a lot of people.

    I want to clear another thing up too. The subsonic 300 Blackout has no where near the energy of a supersonic 300 Blackout round or a .223/5.56. In order to make the 300 BO subsonic, the muzzle velocity must be kept below 1100 fps, most seem to set it about 1050 fps. That gives a muzzle energy of 538 ft-lbs. Needless to say that’s far below the 1100 or so ft-lbs of the supersonic rounds.

    Savage was developing a bolt gun in 300 Blackout and discontinued the project because they could not get acceptable accuracy from it at the subsonic level, here’s what they said:

    “Some time ago, Savage announced it would be chambering the Model 10 Precision Carbine in 300 AAC Blackout. Since that time, we have tested many variants of this cartridge in various barrel lengths and rates of twist. This exhaustive testing left us quite unsatisfied with the accuracy we were able to get from the subsonic loads in this chambering. Accuracy with the lighter, faster loads in this caliber was actually quite good. But we believe the real value in this cartridge lies in the use of subsonic loads for suppressed rifles. Therefore we have decided to scrap the project.”

    I don’t mean to trash the 300 Blackout, but just to state my experience with it. I have since switched to the 6.8 SPC recently and have shot factory Hornady, SSA, and Federal Fusion MSR through it. I have had numerous sub MOA groups, one being 0.48 MOA at 200 yards with Fed. Fusion MSR – my AR Precision barrel seems to like that the best, but the others are good too.

    As with just about everything, application is important. For me, I’m looking for something a bit hotter than the .223/5.56, with comparable accuracy, more energy, and hence more effective range for hunting medium size game.

    Before I conclude, I should point out that Vertex helicopter pig hunting, prefers .223 HPR 60 gr VMAX. I find this stuff to be amazingly accurate. But, again, application. They state they get to under 20 yards for their aerial hunting.

  42. Seems like the real purpose of a 300 Blackout is if you want a 5.56 punch out of a pistol platform, especially if Savage says they couldn’t make the round work in a rifle platform. I was wondering what the difference would be between 300 Blackout, 7.62×39, 6.8 and 5.56 as far as trajectory and energies downrange in 16″ barrels vs 10″ barrels. My understanding is that 300 BO functions best out of a 9″ barrel where 5.56 doesn’t. What’s the truth?

  43. The 30-30 Winchester in a 6lb carbine beats all of these calibers with Hodgdon leverevolution powder = 150gr at 2400+ fps and 170gr at 2300+ fps. All these “black rifle” rounds are a gimmick compared to a Marlin 336 that costs $300 at wally world and 20 rounds for $15 or less. It has taken Elk, bear, hogs, deer, etc.

    If the gun industry did not continue to sell new trends, it wouldn’t get money. But the good old 30-30 was engineered back in 1895 – over 121 years ago. 300 blackout is “neat” but no match for a 30-30 win that is faster and can be collet neck sized for a rifle. 121+ years and still on sale at wally world – Foghorn. 6.8 spc / 300 blackout = together don’t amount to 1% of 30-30’s owned and used over the last 100+ years and current sales.

  44. Been using the 6.8 on hogs in Texas for several years now, I also bought into the 300 blackout craze it made three hunts then became a plinker for the kids. Even with premium supersonic ammo the blackout just does not compare in real world killing power to the 6.8. Just about every 300bo guy that has come on a hunt with me has converted to the 6.8 or the trusty old .308

  45. Interesting.. Old article back in 2012 was a good read, Although I wanted to bring things to mind, Its 2016. The .300blk is more available then the 6.8SPC on many ammo websites (BulkAmmo/LuckyGunner etc.) even Ammo Seek pulled 500+ items for 300blk while 6.8SPC pulled 418 Items, There are double the about of options in bulk ammo available and specialty ammo. Which is not all that surprising since the cartridge is easy to make from spend 5.56 brass. I’ve also noticed that more options are available for the .300blk with optics like an ACOG or VCOG even EOTECH has a .300blk sight (I know Thermal Drift) but the option is not there for the 6.8SPC.
    Both are still very available but time has favored the .300blk over the 6.8SPC and I feel that it is because the .300blk has less obstacles to overcome in the AR15 platform.

  50. “Speaking of special snowflake parts, while the 6.8 SPC will fit in an AR-15 magazine, its actually too fat to work at full capacity. Most manufacturers appear to warn users to only load five or six rounds to avoid bulging the magazine.” —— Why mention this? This is why multiple manufacturers (C-Products, Barrett, PRI, etc) make stainless steel mags that have shallower stiffening ribs. For a standard length magazine, that fits in standard mag pouches, you only lose 2 rounds. But if you want 30 round mags, they are available…. and have been since at least 2006, when I built my first AR pistol in 6.8.

  51. AAC basically copied the .300 Whisper. JD Jones had been developing it far longer than AAC – like many other cartridges it has a few dimensions tweaked and voila, a marketing campaign started up to sell more silencers. Most of the demand tho? Was for 16″ deer rifles.

    Before the .300 Whisper, the round was a wildcat to be used in 20″ AR16s in the early years of 3Gun. Attending the First SOF Invitational, I got an earful from competitors – remember, they were INVITED – who came with .30x45mm wildcat rifles to compete. The rules were being challenged, because at the time, M16’s were considered very much poodleshooters incapable of winning a war. Wonder why. The rules called for a .30 caliber Battle rifle, and the ranks were largely M1A’s, FNFAL’s, and the G3, otherwise known as the HK 91. Said smaller rifles rebarreled to shoot the .30×45? Were shown the door. The rules writers would not concede.

    That is the real origins of the .300 Blackout – and end run around 3Gun rules outlawing the M16 in competition. A 20″ barreled weapon meant for competing at distances up to 400m, and the holdover would have been a significant issue. It still is – in a 16″ rifle, it loses velocity and drops even quicker. Well before the 6.8 does. For shooters who don’t practice much and who can’t afford the commercial costs of buying ammo, it’s not a better choice.

    Which is why, when 3Gun did finally capitulate and opened it’s competition to M16’s, 5.56 as the one and only round to win. The .30×45? Handloaded it could be cheap, but that trajectory? Non competitive. Again, from their, JD Jones saw it’s potential as a suppressed round, and marketed it as the .300 Whisper.

    The more you know.

    • I was going to say that. Thanks for saving me the trouble. More marketing smoke and mirrors, aimed at those who don’t know, or don’t care, about the rip-off factor.

  52. 6.8SPC absolutely blows 300BLK away in barrels as short at 8in and if you get a tight twist barrel from Bison Armory you can stabilize heavy subsonics with a far better ballistic coefficient than ANY .30 projectile could ever hope for.

    LWRC’s Six8 UCIW is an 8″ 300 meter efective weapon delivering 30-40% more energy than a 300blk with the same barrel length.

    Look up Michael Bell’s 300blk, 6.8SPC and 7.62×39 comparison testing on YouTube. You’ll be impressed to say the least.

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