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pix882467434The 300 Blackout round is certainly well-liked by certain members of the editorial staff here at TTAG. It’s a great round for a number of reasons – namely it will work in a standard 5.56/.223 AR-15 with only a change in barrel needed. Every other component in your standard AR-15 build remains the same. If you make the switch, you get a very capable dual purpose round. Full power 300 BLK 123 grain ammunition matches the ballistics of the 7.62x39mm AK round and in a 9 inch barrel has 37% more energy than 5.56mm M855, and 9% more than 6.8 SPC TAP 110. In fact . . .

From a 9-inch barrel, the 300BLK has more muzzle energy than 5.56mm M855 from a 16 inch barrel. When 300 BLK is used in a 16-inch barrel, it has 23% more energy than 5.56mm M855 from a 16 inch barrel – with much higher-mass projectiles for a more dramatic effect on the target.

If your mission calls for quiet work, switch to a 220 grain subsonic bullet and you’ll be putting suppressed rounds on target that are just as stealthy, but hit harder and penetrate deeper than the 9mm rounds fired by the MP5-SD – the defacto standard for silent killing. The true beauty of the 300 BLK round, though, is that an operator doesn’t need to make a decision one way or another before deploying – he simply takes a loadout of both types of rounds and can adjust to mission profile changes on the fly.

So, with all those benefits, why aren’t more people using 300 BLK? Simple – a lack of available ammo. While no ammunition is particularly easy to find these days, you’re a lot more likely to run across the odd box of 9mm or 5.56 mm than you are a box of 300 BLK. And when you do find some, you’re likely to pay exorbitant prices for supersonic loads. As for subsonics – well – good luck with that.

The good news is that reloading for the 300 BLK is pretty easy. Being a rifle round, you will start with a cost-effective single stage press (or maybe a multi-station turret press).  We’ve done a few segments here at TTAG on reloading. Aside from my two-part post on the Cost Benefit Analysis of Reloading (Part One and Part Two) Foghorn did a nice post back in April 2012 entitled Reloading for Dummies with really nice step-by-step pictures and a video. And Foghorn’s video centered on turning down .223/5.56 cases to be used to load 300 BLK.

The whole turning-down-the-brass thing has been the main thing keeping me from reloading 300 BLK. Assuming that I can find the time to do the actual turning, there’s also the case prep that needs to be done after you have shaved the brass down. Quite frankly, this has always seemed to be more trouble than it was worth. I checked out prices of new 300 BLK brass and even if you could find it, I generally could purchase boxes of loaded supersonic rounds for not much more than the brass would have cost me.

While trolling Gunbroker, it occurred to me that I could probably buy 300 BLK brass online (duh!) and that led me to Carolina Brass’s auctions. Carolina Brass is a small, family run company by husband and wife John and Jayme Bowman that procures used brass, cleans, inspects, de-primes, and resizes a number of different calibers. They don’t have a website, but they do have a Facebook page and you can always find them with a number of ongoing Gunbroker auctions.

For the 300 BLK brass, Carolina starts with ’09 Lake City 5.56 once fired brass.


All of the brass has the same headstamp which helps with consistency.  The brass is first cleaned and polished including a final polish in stainless steel to get that new car shine.  It is then deprimed using a Dillon Universal Depriming Die and trimmed to 300 BLK length using a Dillon RT1200.  All cases are trimmed to no longer than 1.355 +/- .003 to fall within SAAMI specs, which should allow you to reload several times before having to do any trimming  yourself.  The cases are then swagged using a Dillon Swagging tool to remove the military crimp from the primer pocket.

What sets Carolina Brass apart is the next step they take – they actually resize the brass for you using a Forster Bench Rest 300 AAC Blackout Die so the brass you get is ready to be reloaded – no need for you to lubricate the cases and do the sizing yourself – all you need to do is prime the case, pour the powder, mount your bullet seating die in the press and go to town.

Besides doing the resizing, Carolina Brass uses a Wilson Case Length gauge during the processing operation to spot check the case neck and overall case dimensions


Now, this certainly sounded to be too easy to be true, but I was willing to give it a shot.  The brass shipped quickly and I ended up paying a little over $100 for 500 pieces, which worked out to about .20 per case.  I used my RCBS hand primer to seat small rifle primers in about 50 or so cases and then used my Hornady lock and load Auto Charge Scale to meter precisely 9.9 grains of Winchester 296 powder.



Since I was interested in evaluating the performance of my Thunder Beast 30P-1 suppressor and my new AAC 9 inch 300 BLK upper, I used Sierra Match King HPBT 220 grain bullets.  I cranked out a few dozen test rounds and headed off to the range.  They performed flawlessly.  All of them were under the subsonic threshold and I had no failures to feed or extract.  Looks like we have a winner here.

So, how do the economics look?  Well, assuming I use fresh brass each time, .20 for the case, .06 for the small rifle primer, I can get about 700 rounds out of a 1 pound jar of Win 296, so that works out to about .04 per round and we are at .30 per round before the cost of the bullet.  For my 220 grain Sierra HPBT rounds, I have been paying roughly $50 per  box of 100 bullets, so add .50 to our cost to bring the grand total to .80 per round or $16 per box of 20.  A quick check of Midway USA has the Remington factory loaded 200 grain subsonic rounds priced at $20 per box, so I’ve already saved $4 for every 20 rounds.  If I reuse the brass, that brings my cost down to .60 per round or $12.00 per box of ammo – a savings of $8 over factory loaded ammo.  Of course Midway (and just about everyone else) is out of stock on the 220 grain 300 BLK, so it’s kind of a moot point – you need to build your own if you want to shoot any today.

If we look at supersonic rounds, the reloading picture gets even brighter.  120-125 grain bullets are a lot less expensive and while they are not going to be cheaper than 5.56 ammo, you can get fairly close while still shooting a larger and more powerful round.

In my mind, the major stumbling block for 300 BLK acceptance has been the lack of availability and cost of factory loaded ammo.  This is not going to change in the short term, but folks like Carolina Brass make the reloading process ridiculously easy.  For not a lot of money (see Foghorn’s post referenced above) you can buy what you need to put Carolina Brass’s offerings to use.  300 BLK is a great cartridge, reloading is not as hard or scary as many people think, and Carolina Brass has made the job even easier.

Update: I exchanged emails with John, one of the owners of Carolina Brass after he read this article and he shared the following additional information with me – mainly to address my comment below about the lack of a website:

“I wanted you to know that we purposefully don’t have one  [website] because we like to have the interactions with our customers…we like to learn more about their shooting experiences and we know it sacrifices, possibly, some sales, but its worth the knowledge and the personal service for us.  We can always sell direct and then people can avoid the auction wait, and we recently have made most of them 1 day or fixed price to alleviate the time issue.”

Makes sense to me given the family business philosophy here.  It also highlights one of the great things about being in the firearms business.  A lot of the people who start or work for companies in the firearms area do it because they are truly committed.  You may, for example run a convenience store, but chances are you are not all that passionate about selling groceries and lottery tickets.  You start a firearms business, its probably because you love guns and really look forward to interacting with others with the same interests.

Carolina Brass 300 BLK Cases
Price: About $50-$60 per 250 pieces (price varies as all lots are sold at auction)

Ratings (out of five stars):

Feel & Function * * * * *
The brass looks good and on the four dozen or so rounds I tested, I was able to prime, drop powder, seat bullet, and go.  No failures to feed, fire, or extract.

Overall Rating * * * *
The only way this could get better would be with an online store and fixed prices.  I get the whole auction thing, but besides having somewhat variable pricing, you may need to wait a day or so for the auction to close before your brass can ship.  The problem of course is that this is a small family operation and therefore is limited as to how much they can process.  Here’s hoping that their business builds to the point where they can hire some help and become a real player because they make a good product.


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  1. The subsonic may have an “on paper” advantage over the 9mm you describe…..But how is bullet performance on a .30 projectile made for a rifle when shot at 1,100 fps?

    My thinking is that the 9mm would be a much better bet if your need allows the use of hollow point ammunition. Those .30 caliber bullets just weren’t meant to perform at those velocities.

    • There’s constant debate over this at the 300BLK forum. Conventional wisdom says the subsonic rounds don’t penetrate well or hollow points won’t expand. But there are a number of guys who have made clean kills on deer with subs. While I’ve yet to see a direct comparison vs 9mm subsonic, I still think the round is neat in that it allows for a rifle to have capabilities that mimic either an AK47 or a suppressed MP5 with the simple swap of a magazine, all out if the obiquitious AR-15 platform. A 300BLK SBR is on my wish list.

    • FWIW, here is some info on the 300 BLK round.

      I don’t have the experience to judge it one way or the other. One thing to bear in mind is that the 300 BLK was designed for military use initially and the military cannot use hollow point or other expanding bullets due to the Geneva Convention. Since military users are going to have FMJ coming out of their guns whether its a .30 rifle or a 9mm SMG, there may be some advantages to 300 BLK in subsonic. According the the writeup referenced above, the 200 grain subsonic 300 BLK outperforms the 9mm both in long range accuracy and penetration.

      • Not everything is FMJ anymore. Ballistic
        tipped rounds are becoming the norm.
        Because there is already a massive market and
        manufacturing setup for .30 caliber bullets with
        tips, the advantage goes to the .300 Blackout.

      • No, No, No, Yes, Yes. No, it was not made for the military, it was a commercial venture that fit the now defunct caliber competition. No, the geneva convention does not mandate FMJ. The HAGUE convention says that signers would refrain from using expanding ammunition. If someone defied it, or you’re fighting someone who didn’t sign (like a terrorist group), all bets are off. Yes, subsonic rounds are essentially a .45 with triple the range, and .300 is often loaded to a higher degree of precision, and the guns that chamber it are more accurate than their x39 counterparts.

        • As to the development of the .300 Blackout, Robert Silvers, director of research and development for AAC, said: “We started development in 2009, but most of the work was done in 2010. A military customer wanted a way to be able to shoot .30-cal. bullets from an M4 platform while using normal bolts and magazines, and without losing the full 30-round capacity of standard magazines.

    • Excellent question, I have been concerned about the same question. For example, is the 220g bullet specifically designed for subsonic use, or is it some off-the-shelf bullet designed for a 2500fps loading? If the latter, I would have zero confidence in any expansion, regardless of the bullet design (HPBT or whatever!). Since there has been no mention that I have seen regarding special subsonic bullets, I would agree that, at least for the time being, hunting should not include subsonic 300 Blk ammo.

      • A subsonic 200 or 220 grain .30 bullet is going to upset and yaw in tissue on impact. Doesn’t need to expand or fragment to do massive damage at that point, you have an >1″ long bullet with more effective frontal area than any expanding bullet.

  2. The 300 BLK absolutely, positively does not surpass the 6.8 SPC on energy or velocity. I really wish a TTAG would stop printing this error. From a 16″ barrel, a 6.8 can push a 110 grain TSX to 2700 FPS plus, or a 140 bullet in excess of 2400 FPS, for more than 1800 FPE (Wilson Combat and Silver State Armory factory data confirmed on 6.8 forum). That is about 400 more FPE than 110-125 grain 300 BLK supersonic loads. Standard pressure loads are a Avila LE from numerous manufacturers that exceed 1600 FPE.

    The BLK is cool, but definitely does not offer more power or range than the 6.8 SPC or 6.5 Grendel. / end rant

    • I guess it depends on where you get your information. According to this site:

      9-Inch AAC Blackout Ballistics @ Muzzle:
      5.56mm – M855 2558 ft/s, 901 ft-lb
      300 BLK – 155 gr SMK 1785 ft/s, 1096 ft-lb (22% over 5.56mm)
      7.62x39mm – 123 gr* 2022 ft/s. 1117 ft-lb
      6.8 SPC – Hornady TAP 110* 2157 ft/s. 1136 ft-lb
      300 BLK – 123gr MC 2130 ft/s, 1238 ft-lb (37% over 5.56mm, 9% over 6.8 SPC TAP 110)

      so, to clarify, we are not talking about ballistics out of a 16 inch barrel (which 6.8 does indeed toast the 300 BLK on), but rather the 9 inch barrel. Quite honestly, the 9 inch ballistics are what make the 300 BLK exciting. I’m not particularly interested in the 16″ version all that much.

      I will edit the post to clarify the barrel length thing

    • Find me a subsonic 6.8 load that will beat a subsonic 220 grain blk load. Also show me a sub 6.8 load that will cycle an ar.

  3. The versatility of the BLK is one of its more attractive qualities IMHO- run a stable subsonic round out of pretty much any length barrel you like and a simple mag change to supersonic ammo gives you high velocity reach- the 5.56 round tumbles quickly out of short barrels and 5.56 weapons dont run well on subsonic ammo.

    Also the BLK uses all the same parts as a standard AR rilfe except for the larger barrel- which can be handy if you want to experiment without lots of investment

    I will stick with the BLK over a 9mm every day of the week for a carbine caliber

    • No, a 5.56 does NOT tumble quickly out of a short barrel …provided you chose a bullet that is compatible with the barrel’s twist. If it does, it’s operator error, not the 5.56 that’s to blame.

      The 5.56’s lethality is almost entirely wrapped up in fragmentation. Even the best 5.56 ammunition — arguably, the 77-gr Black Hills MK262 — will lose the velocity necessary to produce fragmentation well before it will slow to a velocity at which transonic instability will take effect. Regardless of barrel length, the effective range of a 5.56 is determined by the maximum range at which it reliably will produce fragmentation. 5.56 SBRs _do_ have a short max effective range, but it’s because of loss of ability to fragment, NOT because of loss of stability (if anything, it’s just the opposite).

      Ultimately what put me off the .300 BLK/AAC is 1) the lack of energy at SSS velocities, and the lack of bullets that will perform reliably at SSS velocities. Even if you found a 220-gr (jacketed, I’m not shooting cast bullets through a suppressor) bullet that would perform reliably at SSS velocities, it still wouldn’t have significantly more energy than a 231-gr hardball from a .45 ACP 1911A1. Not what I’d call ideal for HD/SD. Which is exactly why I went with .450 Bushmaster for a dedicated subsonic platform. I have the option of up to 600-grain bullets, so it’s quite the thumper. And it shares a common case head with the .30 Remington AR cartridge, so I swap barrels and I have a .308 caliber AR with better energy than a .30-30 Winchester and about the same as a 7.62 Warsaw in an AR15 chassis.

      If it weren’t for the Bushmaster’s compatibility with the .30 RAR, I’d have gone with a .458 SOCOM.

  4. I’m getting 2240+- fps with the 110 grain Barnes in my 16 ” bbl.
    1800 +- fps with 147 grain M-80 ball. This using H110 powder.
    I really like this round. And as the Barnes is all copper, you can use it in the Condor sensative, lead-free areas in CA for pig hunting.

      • If I accurately recall some of Tom’s posts, he’s pimpin’, errr huntin’ all over the world.

        Why he chooses CA over other more fertile hunting grounds, I cannot understand.

        • Pigs are hard to come by in Oregon, most are found on private land where they won’t allow hunting.
          NorCal is an 8-10 hour drive to do some whacking and stacking.

  5. I was looking into building a new ar platform for hog hunting with a suppressor. Would the 6.5/6.8 be a better round compared to the 300?

    • My experience is on the 6.8 side with a 16″ barrel. You’ll get more range and energy with such as setup, but the 300 BLK excels as a suppressed round (or so I’be “heard”). As of a few months ago, 300 BLK ammo is very tough to purchase, and the cost for in stock ammo was $2 / round plus. I got Silver State Armory 110 grain pro hunter for just over $.80 / round shipped. Prices are constantly changing, of course.

      If you want more range and power, go 6.8. If you want sub / supersonic versatility and can get your hands on ammo and / or reload, I’d go 300 BLK.

  6. You made a mistake there… ALWAYS and I mean always recommend the person you are writing to about reloading use a load 10% lower than the one you recommend and work their way up to what works for them. This is standard practice for all reloading articles for liability reasons. Powder and primers are hard to come buy these days. Brass is loosening up but primers are still scarce.

    • Actually, the 9.9 loading I used WAS the starting load. You need to be really careful when slowing a round that is normally supersonic down to subsonic speeds and even more careful when you are trying to get a loading that will cycle a semi-automatic rifle.

      Underloading a round that ends up not having enough powder to clear the barrel sets you up for a situation that has the potential to be even more catastrophic than an over-pressure cartridge.

      That said, anyone with common sense would not take what I wrote in this article and consider it reloading guidance. I don’t for example say what the OAL of the finished cartridge should be. Without that info, you can’t safely make a loaded round of ammo.

      • And there is the rub. You didn’t mention that you were at the bottom of the range which one could easily underload the round. COL does not matter as long as it is able to make it in to the chamber from the mag in an AR15. The bullet will seat itself if your Ogive is out too far. It can lead to funny shots but the powder charge is more important. I may have been reloading for only 10 years for competitions but I have read ALOT of reloading articles. I just wanted to point out a common and much needed CYA by the reloading publications online and offline.

    • Be very careful with advise like that with this round. Especially when talking about subsonic with say H110. You actually want to only go about 3% below max with this stuff as going too far gives a chance to get all your powder igniting at once causing a pressure spike and possibly a kaboom. It’s because it takes up so little case room and the entire load can be exposed to the spark from the primer not just the powder by the primer itself. If you go low with some of these denser powders in 300 blk you want to at least use some filler to keep the powder from settling away from the primer. 300 BLK is definitely an odd duck when it comes to reloading, especially subsonic with those dense powders.

      • Ironic that you’re talking about “safety” at the same time that you’re recommending the use of fillers which have been condemned by knowledgeable reloaders for decades now.

  7. I reload 147gr supersonic rounds for about $0.12 each and and 175gr subsonic rounds for about $0.17 each. That’s with scrounged brass and bulk bullets.

    The 175gr is the lightest bullet I’ve been able to shoot subsonic and still cycle the slide. That’s out of an 8″ Noveske and AAC SDN-6 on an AR “pistol” (no SBRs in WA).

  8. Anyone have a recommendation for a barrel in this calibre? I was curious so I looked at Gunbroker and the prices are all over the place. I ask more out of curiosity.

    • Mike, I’m building a 7.5″ barrel (1:8″ twist) and I’ll let you know how it chronos with every load I put through it.

  9. Every time you guys talk about 300 blk it makes me feel like a huge failure at life for not being a reloader. One more article about it and I’ll have to break down and get a single stage press.

    I want a suppressed 300 blk sbr even more than I wanted an Eames lounge chair when I was hipsterrific.

    • There is absolutely nothing wrong with getting a single stage press for a single caliber. That is how I started – I wanted to reload for my 300 Win Mag. Then I added my .338 Lapua to the mix. Then my .44 Mag revolver and it got going from there. If you plan to shoot a lot, you can definitely recoup your investment in a basic reloading rig on 300 BLK alone.

  10. I am reloading supers with a single stage setup. My cost per round for pro hunter 125 grain spitzers is 42¢. With the next batch that is going down to 37¢. Making the brass really isn’t too bad after you do it a bit. My chop-size & de-prime-groom works pretty well.

  11. Re-using 223 brass, mine come in around 29 cents, supersonic, using Hornady 150gr FMJBT (use these on my 308 also), CCI primers and A1680, all purchased bulk (1,000 each projectile/primers, 8 lb powder from MidSouth). Using a 2″ cutoff saw from Harbor Freight. Normally I reload the 223 until the neck splits, then cut it it off and reform using a Lee case trimmer and Lee 4 hole turret press with the 300 blk dies. Seems to work pretty good. Use a 4×7 42mm NCStar AR style scope.

  12. Anyone else having problems finding the Carolina Brass FB page? Link above says doesnt exist, only Carolina Brass I get in searches are bands…

  13. After reading all the hype I decided to build a 300blk. I built a 16″ AR carbine. Using Lee dies, a Wilson case gauge, Lyman reamer and a Harbor Freight chop saw turning 5.56 cases into 300blk was easy. I could load and shoot them pretty cheaply compared to buying ammo. The performance characteristics of the round did not meet my needs. I live out on the high plains and because of all the open areas very few of my shots unless just on a range, are under 100 yards. Discovering that the cartridge was limited in range and performance at the distances I shoot made me sell the rifle. I have a friend with the 6.5 Grendel and it is a more potent round out here. Just my experience.

  14. I think some people are missing the point. Every time 300blk is mentioned 6.8 5.56 7.62×39 and 6.5 shooters get all up tight over this cartridge. Point is it can be loaded cheap and it’s a versatile round. It has more reliable feeding and less prone to break extractor “7.62×39 & 6.8″ uses common mags. No it doesn’t have long range capabilities of a 6.5 grendel or high velocity like in an 85gr 6.8 but it’s a well rounded cartridge with a lot of accuracy and knock down power. You can’t successfully load 150gr bullets in a 6.8. 180gr nosler out of a 10.5” 300blk barrel is nasty on impact within 100yds. Wide range of bullets. Every cartridge has it’s pros and cons. If your into short barreled weapons that are handy lightweight multi purpose compact and cheap to shoot with that can take medium sized game within 150yds 300blk is the way to go. Let’s face it 30cal heavy bullets work and I’d rather hunt with that than some skinny fast bullets.

  15. The wife is considering getting me a suppressed 300 BLK SBR or AR pistol with the SIG brace for anniversary 25 in a couple years. Gotta watch the pennies but am I lucky or what?

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