The Ultimate Urban Carbine Cartridge: 300 Blackout
September 23, 2013
Over the last few months I have become a big fan of the 300 AAC Blackout cartridge (officially abbreviated 300 BLK). The primary reason for this is that for years I have believed we have been in need of a good carbine cartridge, a successor to the .30 M1 Carbine, and I think that the 300 AAC Blackout fits this need perfectly.
The .300-.221 wildcat cartridge (or .300 Fireball) has been around for quite some time, and was popularized most recently by J. D. Jones as the .300 Whisper. Jones took a .221 Fireball case (which has the same size base as the .223 Rem.) and necked it up to .300.
He was thinking more about the usefulness of the cartridge in suppressed AR-15s. Jones preferred to stuff big bullets into the little cases, favoring the 220-grain Sierra MatchKing bullets traveling downrange at about 1000 fps.
Remington recently introduced the .300 AAC Blackout cartridge. The dimensions of the two cartridges are identical, but the Whisper is still a "wildcat" cartridge. The Blackout has been SAAMI approved, which means that any ammo made or guns chambered in that caliber have to be made to certain dimensions and specifications. The Blackout tends to be loaded to higher pressures. While it is safe to shoot Whisper ammo in a Blackout-chambered rifle, the opposite is not always true.
Remington focused most of its effort on the Blackout's capabilities for hunting and defense through the use of supersonic ammo. Much of the commercial ammunition made for the Whisper/Blackout features 110-grain bullets heading downrange at 2300+ fps. A .30 110-grain bullet? Why does that sound so familiar? Because it is that caliber and bullet weight combination you'll find in the M1 Carbine.
The straight-walled .30 Carbine cartridge threw a 110-grain round-nose pistol-type bullet downrange at just under 2000 fps. Even as carbines go those are relatively anemic numbers, and while you will find a number of people who decry the carbine as being underpowered, you can find an equal number of people (including combat veterans) who loved it.
It was small, light, handy, held a lot of ammo, and was quick to reload when compared to the other shoulder arms of the day.
The Blackout, on the other hand, is pushing the same weight and diameter bullets over 300 feet-per-second faster, plus they are modern rifle projectiles, not downsized FMJ pistol slugs. Not only that, the cartridge was designed for the ubiquitous AR-15 platform. When it comes to performance and utility, I feel the 300 AAC Blackout is the modern evolution of the M1 Carbine cartridge, and that's something we need.
AR-15s are everywhere. They are used for target shooting, competition, home defense, even hunting. Police department tactical teams have increasingly gravitated away from shotguns and HK MP5 submachine guns toward ARs as well.
But this is not necessarily a good thing. One size does not fit all.
The small, fast .223 bullet shoots flat at distance, but does that matter to anyone concerned about self-defense? Most defensive rifle shots taken by civilians or law enforcement will (and have been) taken at what most riflemen would consider "urban" or even point blank ranges, well inside 100 yards.
Pat Rogers, a retired Chief Warrant Officer of Marines and retired NYPD Sergeant with a wide and varied background in the CT Community, runs E.A.G. Tactical. For almost 20 years E.A.G. Tactical has been teaching military, police, and civilians how to win the fight.
"The majority of the carbine training we do is 50 yards and in," Rogers stated. "This is for several reasons. One, it's hard to find a range much longer than 50 yards nowadays, although occasionally I train military out to 300 yards. Second, whether you're police or civilian, you'd be hard-pressed to justify a defensive shooting further away than that. Most of the police we see are using their carbines at pistol distances."
I personally know a Detroit-area police officer who has been involved in four duty-related shootings. He used a carbine at pistol distances for all four.
Also, despite its popularity and the fact that our troops have been employing it against enemy combatants for the better part of 50 years, the round still has many detractors who say that a relatively small and light .22 bullet is particularly unsuited for anti-personnel use, much less barrier penetration.
Heck, the .223/5.56 is not legal for hunting anything other than small game in many parts of the country. When it comes to barrier penetration, mass beats velocity, and if there's one thing you'll find in an urban setting, it is things which do their best to stop bullets. Automobiles are amazing bullet traps.
For decades in this country the role currently occupied by the AR-15 was fulfilled by the M1 Carbine. I think we're long overdue for a general purpose carbine round for the American citizen. Something that hits reasonably hard while still being soft shooting, can be used for hunting and self-defense at close to medium distance, and runs in an AR. I think the 300 AAC Blackout is that cartridge, and believe it is only fitting that a modernized M1 Carbine-type cartridge is now available for the AR platform.
The only thing required to change calibers to 300 BLK is a new barrel, although let's be honestâ€”most AR owners will just buy a second complete upper receiver/barrel assembly. There are many alternate-caliber AR variants. One advantage the 300 BLK has over them is that the ammunition, with only a few exceptions, feeds from standard GI MilSpec magazines.
As I write this there are no ARs to be found for sale anywhere due to panic buying, and magazines are either scarce or priced exorbitantly. The fact that 300 Blackout cartridges fit and feed from most standard AR magazines has now become a huge selling point.
So what does "most" magazines mean?
Traditionally, the .223/5/56 case neck indexes on the internal forward rib of the magazine. When firing Blackout rounds with shorter overall lengths (i.e. supersonic loads) the rib contacts the bullet on its ogive, and this usually isn't a problem, especially when using modern magazines such as Lancer L5 AWMs or PMags, or GI magazines equipped with non-tilt (i.e. Magpul) followers.
Subsonic ammo for the Blackout is loaded with longer and, usually, thicker projectiles. With longer rounds, especially those with heavy bullets loaded to full mag length, the ribs tend to push the noses together and have the rounds interlace like fingers in the magazine. Depending on the gun/ammo/magazine, this may cause some reliability issues.
Prior to the panic buying of December 2012, Bill Alexander of Alexander Arms was working with D&H Magazines to produce a Blackout-specific magazine with a redesigned forward rib. He had just received some prototypes when everything went crazy, and now D&H (and everybody else who makes anything having to do with ARs) has been running as fast as they can just to stay in one place.
Whether we ever see Blackout-specific magazines now seems entirely dependent on what new legislation is enacted by those politicians who hate the very idea of guns.
With the 300 Blackout in mind as perhaps the ultimate urban defensive round for civilians (that includes law enforcement, for those of you ignorant of exactly what "civilian" means), I decided to put together an Ultimate Urban Carbine chambered in this relatively new cartridge.
If You Build It, They Will Come
Everything starts with the receiver, and I had a stripped lower receiver sitting around. "A lower is a lower is a lower" as Dave Fortier likes to tell me, and it's true, to a certain extent. I had a standard lower receiver from a company now out of business, not one of the thick billet types, and it would serve my purposes just fine.
The first time I ever assembled an AR-15 receiver was when I was in high school. I had a stripped lower, a lower parts kit, and borrowed a buddy's completed lower receiver so I could see what the finished product was supposed to look like.
For tools, I had a standard hammer, a vise, and some sort of oversized punch. I messed up putting the roll pin in for the bolt catch, so that the magazine followers never had quite enough oomph to lock the bolt back, but other than that was able to completely assemble my first lower back 25+ years ago without any instructions, just by eyeballing the finished product. Considering I have absolutely no mechanical skills, that says something about the simplicity of the AR-15 design.
This time around I hadâ€¦Brownells.
Whatever you need when it comes to AR-15s, whether that's parts or the tools to assemble them, Brownells carries it. The only downside to their vast selection is that it's soâ€¦vast. Sometimes tracking down exactly what you need can take some work.
Wanting to do everything the right way, I remembered an email I'd received from Brownells not too long before spotlighting the free gunsmithing videos they have on their website, specifically videos about how to assemble an AR-15 lower receiver.
I know there are dozens of YouTube videos detailing how to assemble this or that, but considering they are of unknown provenance I wanted to do things right. I clicked on the green LEARN tab at Brownells.com and discoveredâ€¦609 articles/videos covering gunsmithing of the AR-15/M4.
Trying to track down what I needed through the Brownells website wasn't working as easily as I'd hoped, so I took a shortcut. I Googled "Brownells assembling lower receiver", and that got me right to the page I needed.
There were seven videos explaining and demonstrating very simply how to assemble a lower receiver, and in no time I had a completed lower receiver assembly. I'd been wanting to try the new Magpul rubberized MOE+ grip, so I bought one of those and installed it on the lower.
I despise the standard heavy and gritty GI trigger pull. Unlike some projects I've been assigned, everything going into this gun was either already on hand, or bought with my own money. So, when it came time to decide what fire control system to put in it, I actually wanted to install a Geissele Super 3 Gun trigger, which is a single-stage design with a pull weight about 3.5 lbs. However, I didn't have one on hand, and had no money to buy one. What I did have was the excellent Geissele SSA trigger, a two-stage design with a 4.5-lb trigger pull. In it went.
Step one doneâ€¦now for the top end.
Embracing the urban environs/short range concept, I knew that shorter was better when it came to my project. One of the most fun guns I've had a chance to shoot this past year was the PDW in 300 BLK from Advanced Armament Corp (AAC themselves), which featured a 9-inch barrel tipped by a suppressor, for an overall length the same as a 16-inch barreled top end.
Most people, however, just don't want to go through the hassle and federal paperwork required for an SBR (short barreled rifle) and sound suppressor. I decided a 16-inch top end would be the way to go.
Due to the big push from Remington/Freedom Group, finding companies making top ends chambered in 300 AAC Blackout was not difficult at all. While I had a nice top end from Wilson Combat on hand, I decided ultimately to go with an upper from Alexander Arms.
Alexander Arms has made a name for itself specializing in non-traditional calibers for ARs, specifically .50 Beowulf and 6.5 Grendel, but they recently began making ARs chambered in 5.56 NATO and 300 BLK.
My rifle had a 16-inch fluted stainless steel 1:8 twist barrel with a carbine-length gas system, their rifle-length Mk 10 handguards made of G10 composite, and was tipped with the very effective Blackout flash hider from Advanced Armament Corp.
I switched out the GI standard charging handle of the AA upper for a Gunfighter charging handle (Mod 4-Medium) from Bravo Company. Not only is the BCM version strengthened, but it features an oversize and serrated latch for secure manipulation. There are a number of companies who make oversize charging handles, but I haven't found one yet better than the BCM.
The AA Mk10 handguards are modular, and accept rail sections just about wherever you want to screw them on. I installed two 2-inch rail sections at the front of the handguard, one to mount a front sight, the other at 9 o'clock to accept a sling mount and flashlight.
Any serious rifle should have back-up iron sights, and for this rifle I liberated a set from another rifle I had. The Bravo Company folding battle sights, made by Troy Industries, are as good as any sights out there, and better than most. As for an optic, considering I was putting together a carbine designed to be used at urban distances, any scope with magnification seemed a bit superfluous.
The EOTech Holosight has the red dot reticle against which all others are judged when it comes to speed and ease of use. There are lighter red dots, and red dots which provide a lot longer battery life (such as the Aimpoint Micro), but I've yet to find anything which can compare to the reticle and field of view of the EOTech. I had a relatively new EOTech XPS3 on hand, and slapped that on top of my receiver between the sights.
Slings are always a good idea, and I attached a VTAC (Viking Tactics) 2-point sling as well. I've played around with a lot of single-point and convertible slings, and I just haven't found anything that is as useful as a good 2-point sling, and the VTAC, with its padded strap and quick adjustments, is as good as any sling out there.
In a box of spare parts in my basement I found a very cool and minimalist rail sling mount with QD sling socket which I attached at the front of the forend. I had no idea where I got it or who made it, and none of my gunwriter friends could ID it, so I went to the ultimate sourceâ€”I keyword searched "rail sling mount" on the Brownells website and determined that it is the 10/2 Quick Detach Swivel Mount from Wilson Combat.
The Hell With Diets
As I was thinking about how to put this AR together, I realized that I've always said carbines should be as short and light as possible. However, a few things made me rethink that position, at least for this project. An urban carbine, by definition, isn't going to be carried on long cross-country treks.
Weight isn't as important as if I was putting together a SEAL Recon rifle designed to be humped up and down the Hindu Kush. While the 300 Blackout is no thumper, the supersonic loads provide about 25% more recoil than a .223/5.56. That's not bad at all, considering the .223/5.56 is a pussycat, but I wanted to put together a rifle that allowed for the quickest possible follow-up shots.
Normally, to reduce recoil/muzzle rise and get back on target quicker, the easy solution is to throw on a muzzle brake/compensator. I didn't want to do that. An "urban carbine," by definition, may see indoor use, and rifles are loud as hell even before you start screwing compensators on the end of their barrels. The AAC Blackout flash hider works very well, and looks cool, so it stayed in place.
Once you eliminate a muzzle brake as a way to reduce recoil, what is left? Two thingsâ€”fancy recoil absorbing buffers, and simple gross weight.
Short-barreled 300 BLK rifles designed to wear suppressors have pistol-length gas systems. Standard barrel length Blackout rifles have carbine-length gas systems, and are meant to be used with standard carbine buffers.
With standard buffers, the same rifle can shoot both supersonic and subsonic ammo all day long without a hitch, whether or not there's a suppressor mounted on the end of the barrel. Start changing out the standard weight buffer, and all of a sudden you're going to have problems. I didn't want problems, and so left the standard carbine buffer in place. That left weight as my only option for reducing recoil.
Physics rules all. One sure way to reduce felt recoil of a shoulder-mounted weapons system is to increase its weight. A stock that I had on hand, that I used for a previous project, and that I liked a lot in spite of its weight, was the Hammer buttstock from Ace, Ltd.
Advertised as the world's strongest AR stock, this beast of a stock is machined out of aircraft aluminum. One look at it is enough to tell you that it has been specifically designed to be used as a blunt instrument in CQB. Considering serious social engagements which occur in urban settings often happen at contact distance, mounting a stock designed to take impacts seemed a good idea.
The people at ACE were aware that the problem with using a standard M4 stock as a striking instrument is as much the relatively thin buffer tube as the stock itself (which can be easily replaced). The buffer tube tends to bend when struck against hard objects with any sort of force. Bent buffer tubes will stop your rifle dead.
The Hammer comes with a reinforced buffer tube, thicker than normal in certain areas, and a significantly beefed up gusset that locks it to the receiver. How beefed up? The Hammer is specifically designed to be tough enough for door breaching.
The stock has two QD swivel sockets, and tapped sockets on either side of the gusset to install a sling mount, but I wish it had a QD sling socket on the gusset.
The lever to adjust the length of the buttstock can be locked to insure no accidental release/adjustment of the stock. The stock is completely aluminum and steel but for the adjustable polymer cheekpiece. The fact that it weighs close to half a pound more than a standard stock is usually a negative, but for this project it was perfect.
Also, allow me to let you in on a little secretâ€”weight added to the front half of an AR seems to weigh twice what it actually does. Weight added to the rear of a rifle seems to weigh half what it actually does, because of the way rifles balance. That is one reason competitive shooters wielding long, heavy-barrel rifles tend to equip them with stocks like the very heavy Magpul UBR. They balance the rifles, without seeming to add much weight at all. With the Hammer stock in place, my carbine still balanced over the magazine well.
Total weight of my carbine, unloaded and with iron sights, was 7 pounds, 2 ounces. The EOTech XPS3 added another 11 ounces, for a total weight of 7 pounds, 13 ounces. Due to the weight distribution, it felt much lighter. But what about ammo?
Traditionally, a 30-round aluminum GI magazine weighs just about a pound when loaded with .223/5.56 ammo. Considering the standard Blackout supersonic load featured bullets weighing twice the standard 55-grain found in the .223, I loaded a magazine up just to see how much weight difference there would be:
â€¢30-round Colt aluminum magazine loaded with 55-grain ammo: 15 ounces
â€¢30-round Colt aluminum magazine loaded with 110-grain ammo: 18 ounces
Simply changing calibers would mean an additional three ounces added to the total weight of a loaded gun.
The panic buying of late 2012 resulted in one positive, at least for meâ€”it made me aware of E-Lander magazines, available through the Mako Group (www.themakogroup.com). I'd never heard of these Israeli-made steel AR magazines, but the fact that they were still in stock convinced me I should try them out, and bought a few.
While I've never had a chance to examine in detail the steel HK416 magazines, I have a lot of time with SA80 and Fusil magazines, both with steel bodies. The E-Lander magazines, designed for the Israeli Tavor bullpup and M16s, are the best-made steel magazines I've ever tested.
Topped with a self-leveling, non-tilt follower obviously influenced by the Magpul Gen 1 design, these glossy black magazines have a coating that resists a 96-hour salt-spray test. While designed to have GI-spec exterior dimensions, they locked up a little tighter inside my mag well than standard aluminum magazines, but as far as I'm concerned that's a good thingâ€”wiggling mags encourage jams.
Steel magazines weigh more than aluminum ones, and the E-Lander mags were very stout. A traditional GI aluminum 30-round magazine weighs about 4 ouncesâ€”the 30-round E-Lander weighed 7.8 ounces. One of them stuffed with 110-grain Blackout ammo would be six ounces heavier than a GI aluminum magazine loaded with 5.56. My carbine, loaded with a steel E-Lander and wearing the EOTech, tipped the scales at 9 pounds, 2 ounces. As meaty as that is, it didn't feel that heavy because it was so well balanced.
I am not overblessed with an abundance of upper body strength, and yet I still was able to keep the rifle shouldered and on target with just my right hand on the pistol grip.
If a 9-lb AR seems hugely overweight to you, realize that most of our troops, once they've added their quad rail handguard, forward vertical grip, optic, flashlight, laser target designator, and loaded magazine, carry M4s that weigh closer to nine pounds than six.
Thump And Crack
The number of ammunition companies making either Whisper or Blackout ammo is large, and growing. I've tested ammunition from Remington, Black Hills, LeHigh Defense, and Hornady, and done a lot of handloading, but currently my favorite load is the 110-grain TAC-TX from Barnes.
In the gel tests I've witnessed, this bullet penetrates about 14 inches while expanding very nicely. This is a tipped copper solid bullet, which means that it won't shed its jacket if you're shooting through auto-glass or drywall, because it has no jacketâ€”perfect for this project.
If you've never fired a .300 Whisper or 300 BLK, whereas the .223/5/56 round makes a sharp crack exiting the muzzle, the Blackout has a noticeably different sound. It makes a deeper thump, not surprising considering it operates at lower pressures and velocities.
The added weight definitely made a difference when it came time to send rounds downrange. Nine pounds was definitely enough weight to soak up some recoil. Shooting offhand rapid fire at 25 yards (remember, "Urban Carbine"), without using the sling, I found the EOTech's center dot rose vertically about six inches on the target, then went straight back down, with no side-to-side movement.
Recoil back in the shoulder was a gentle nudge, and the rifle was balanced well enough that I could drive the muzzle from target to target without a problem. Using the sling to tension the carbine reduced recoil even further.
While I don't think the 300 Blackout round is as inherently accurate as the .223/5.56, it is not a cartridge meant for use on the line at the National Matches at Camp Perry. It is more than accurate enough for self-defense, as you can see from the accompanying accuracy chart. Also, as effective as modern expanding .223 bullets are at stopping threats, I'm guessing expanding .308 bullets which weigh twice as much work even better. Some (limited) anecdotal evidence from sandy environs that I've heard seems to bear this out.
One big advantage to the 300 BLK when compared to other alternative AR calibers is that Blackout brass can be easily made from .223/5.56 brass. A second advantage is that it is loaded with very common .308 diameter bullets (my favorite handload uses the 125-grain Nosler BT). This is something to think about if, in the future, brass and bullets get scarce.
Between the number of commercial companies selling guns and ammo in 300 Blackout, and the interest from certain Tier 1 spec-ops groups (who are actually getting to play with a specialized 110-grain loading I wish was available commercially), I don't see the 300 AAC Blackout going away any time soon.
My Urban Carbine Project is a work in progress. I still haven't decided on a flashlight mount or light, something a rifle designed for self-defense desperately needs. I believe Impact Weapons Components makes a flashlight mount for the Alexander Arms handguard, but a lack of time and money has conspired to keep one of those out of reach, at least so far.
However, a flashlight will add even more weight to a rifle that is getting a little porky, and I'm not sure I wasn't too successful adding weight to it. Perhaps once I add a flashlight I may switch out the Hammer stock for something lighter, even though I really like the looks and balance of it. Maybe I just need to lift some more weights.
Also, this was the first time I'd spent any serious time using a rubber AR pistol grip with the Magpul MOE+, and I found I did not like it, at all. Why? When flipping the safety on and off, I found the rubber grabbed hold of the inside of my thumb, providing more resistance. When wearing gloves it was even more pronounced. The last thing I want is a rifle that fights me when I try to do something.
Combining the words "urban" and "carbine" in this political climate may seem risky, but law-abiding citizens use guns to defend themselves thousands of times a year, and in doing so for the most part are ignored by the press, who have a different agenda when it comes to talking about firearms.
That doesn't mean it doesn't happen. Most Americans live in urban or suburban locales, and if something really bad happens, the fact of the matter is that a pistol may not be enough to solve the problem, and a modern carbine might be exactly what is needed.