300 Blackout Project

300 Black Project

I refurbished my first AR upper (Recce build) and rechambered it in 300 blackout. 300 blackout has been around for a while, and I chose this chambering because after doing some research, I found myself questioning my previously held beliefs about it.

I consider myself unbiased when it comes to doing reviews and don’t pull my punches even when I spend my own money on things – see my Handl Defense lower review. In this review I’m going to covering like the title states, a 16” 1:6 twist Q 300 Blackout barrel. The upper was assembled by the Giant Panda at Prime Sports, and I picked up my ammo at Security Equipment from some bald not too good looking hapa dude.

BACK STORY

Before we get into the barrel, I don’t think that this review would be complete without some clarification on the origins of the 300 black cartridge. It was created and refined by Advanced Armament Corp. (AAC) at the request of a certain military unit that was looking to replace their 9mm MP5’s. They reportedly weren’t satisfied with the performance of the suppressed 9mm rounds against targets, especially those wearing body armor. AAC stepped in and furthered the development of what was then called the 300 Whisper into the Blackout. The end result of this effort was the original Honey Bader:

Based on the familiar AR family of weapons, no additional training would be needed for units to adopt it, but no military orders were forthcoming. When AAC was sold to Remington, there was hope that the Honey Badger would be sold on the commercial market. However that was not the case and the Honey Badger was relegated to the “Could have been great/good” heap.

The 300 Blackout round itself proved more commercially successful and was adopted industry wide. The hallmark of the 300 Blackout round is versatility. It performs just was well suppressed as it does supersonic. Bullet weights range anywhere from sub 100 grain self-defense and varmint loads up to 200+ in the subsonic variety. Contrary to popular belief the round was not specifically designed, aka optimized, for sub 10” barrels. A lot of shooters were disappointed in the round’s performance when they weren’t getting sub MOA groups at 100 yards, but this round was designed as military round and not necessarily as a national match precision round. The essence of the round was good performance unsuppressed and suppressed.

For those that are interested in the technical specs of the round Mr. Guns and Gear has a good video explaining the different velocities he was getting out of different length barrels with his chrono:

So fast forward to 2017 and you come to heart of this review, the reincarnation of the Honey Badger at Kevin Brittingham’s (KB) new venture at Q.

I was always interested in the 300 Blackout as a round, given the .30 cal bullet out of a 5.56 mm case, but seeing what my friends had to go through to get their systems to work semi-reliably I shelved the idea until recently. The main problem was getting the system to cycle properly with the different bullet grains; the heavier the bullet, the more the AR was like a bolt action and wouldn’t cycle properly. It became a running joke, “You bring your bolt (action) today?”, “Yup!” friend pulls out his 300 blackout upper.

After doing more digging and research I became more convinced the problem wasn’t with the round itself, but the lack of understanding of the system as a whole and what it would take to operate a semi-auto “DI” system. (I put DI in quotes for those gun nerds that will say the AR is not a true DI system.). So I figured I’d go with the guy who was instrumental in the 300’s development.

So I ended up picking up a 16” stainless steel 1:6 twist adjustable gas block barrel from Q:

THE SPECS

You didn’t misread that the two times I typed it before. It is a 1:6 twist rate, which is fast. Why? During development KB found during testing this was the optimum twist rate for BOTH subs and supers. This is NOT to say other twist rates won’t work like 1:7 and 1:8. The gas system is pistol length and is adjustable. My factory block already came adjusted, but you may need to adjust it further depending on the type/brand of ammo you’re using. I turned my block to the full off position, then kept count of the revolutions as I opened up the block again to about 4 ½ full turns, and hoped that would be enough.

I topped it off with a Q produced Cherry Bomb muzzle device:

Pinning and welding this to avoid the NFA is not recommended since that will screw up the threads and prevent you from running a suppressor or muzzle brake. KB is a big believer of tapers before threads. When he first started out he was convinced of the opposite and now realizes how mistaken. The gas block is held in place by a gas index pin and a jam nut which is easy to tighten to ensuring the gas block doesn’t move and misalign the gas port.

And a Q Bottle Rocket muzzle brake:

For those of you that have mechanical backgrounds you may have noticed something about the two muzzle devices and you’d be correct if you were thinking they reminded you of drive sockets. The devices were made specifically to be compatible with commonly available drive socket sizes.

You’ll also notice how the carbon fouling is concentrated at the front of the Cherry Bomb around the ports vs. the threads which would cause a can to become stuck.

Here is a good illustration of how the Cherry Bomb and Bottle Rocket go together. The Bottle Rocket is hollow and that empty space between the end of the Cherry Bomb and the first port cuts in the Bottle Rocket acts as an expansion chamber of sorts. It’s not a lot of space, but makes a noticeable difference in perceived recoil.

Just the tip?

FIRST SHOTS

Not sure how the gas system would react, I picked up 150 grain supersonic (supers) American Eagle, and 220 grain subsonics (subs).

I picked up 100 rounds in the supers and 200 in the subs just to see how the barrel and upper just to see how it would cycle. It….ran….like…..a…..champ. I had brought my torx driver just in case I needed to remove the handguard and adjust the gas block, I didn’t need it at all. I let a few other shooters send lead down range so I could check the ejection pattern and it was consistent between the two ammo types.

My first 5 shot group shredded the left side of my stand with my Eotech 300 blackout.

With the subs, my best 3 shot group at 50 yards was .74 MOA and a 10 shot group was 3.84 MOA. See attached pics.

Some of you may be wondering why I bothered shooting subs out of a 16” barrel since the round isn’t going to be subsonic when it exits and we can’t have silencers here. Both are valid points, but perceived recoil is very different between the two.

Just humor me here since there isn’t a scientific way to express this, but let me try by comparing it to the recoil from a 556 and a .308. If 556 is on low end, and .308 is on the high end of the spectrum, 300 blackout is closer to the 556 end of the spectrum.

Super (recoil) Sub (recoil)
X X
556 I .308 556 I .308

The subs are very mild shooting since they are barely supersonic as they exit the barrel, while the supers are still manageable with a recoil impulse somewhere right in between a 556 and .308.

FINAL THOUGHTS

The Q barrel handled the sometimes temperamental 300 blackout flawlessly. Not a single issue with the gas system or quality of the parts. There is an issue with using standard USGI type aluminum mags, particularly with the subs. The guide wings on the inside of the USGI mags are more pronounced and cause the larger 220 grain heads to cant inwards and thus impinge on the following round causing feeding issues. This happened the first time I tested the upper, and 3 additional times after. After the 4th failure to feed, I unloaded all my USGI mags of subs. As far as I can tell this is only a problem with the subs and not with the supers. I have a little over a 1,000 rounds on this new upper now, because I wanted to have enough rounds through it to where I feel I could accurately gauge it’s performance.

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