.300 blackout terminal ballistics

[Ironman8]

Because 300 BLK was meant to work efficiently in short barrel, you won't need as long a barrel as 308 to attain maximum velocity. 308 rifles are generally 20 - 26 inches, aren't they? 300 BLK will work fine from 16 inch barrel. AND, 16 inch bolt action carbine is a very compact rifle, no matter what action it's built on. As for light weight, because barrel is shorter, barrel can have small diameter and still have same stiffnes as longer one with big fat barrel. So shorter and lighter barreled bolt gun will be fairly compact and light.

There are plenty of 16-18" barrels in .308....look at the LaRue PredatAR/OBR line.

If I did anything in 300BLK, it would be a sub 10" SBR because that is what the round is optimized for....but I will be waiting till the round is more established before I do anything like that.

From what I understand, it CAN be used for hunting, but the .308 will give you longer range performance.

[tpd223]

How would it be more compact and lighter than a 308 if it uses the same action?

There are a few mini .223 length actions out there, I've seen some pretty neat 7.62X39 bolt guns before that were very handy.

[JasonM]

How would it be more compact and lighter than a 308 if it uses the same action?

Because it can be built on a lightweight Model-7 action with a 16" lightweight barrel and be much more comfortable to shoot than a similar .308.

[mkmckinley]

Glad to help Ruben.

An important thing to remember in regards to the 300 BLK is that it is very much still in its infancy. It was announced less than a year ago and lots of exciting development is upcoming.

Yes, you can certainly have your chambers reamed and then be able to shoot any and all ammo safely. There are a number of companies that will do this for a minimal fee, or you can buy your own reamer.

My PERSONAL feeling about this round and rifle is that the primary niche is hunting or defense use (ideally in an SBR) from CQB out to 250m (with supersonic ammo)

It can go a lot further than that of course- Robert tested the supersonic ammo and it remained supersonic out past 600m, but it is not designed to be a long range round... you'll have to move up to 308, 260, etc for that.

It SHINES in very short barrels where traditionally the 5.56 has lacked power and had too much flash/blast. It is downright gentle on suppressors compared to the 5.56. AND it has factory subsonic ammo that will cycle an AR.

It also has a very important application as far as offering a 30-cal solution for ARs for hunting. Not to mention being able to build up a very compact and light bolt gun for hunting.

And, at the end of the day, if you decide it's not for you, just switch barrels and you've got a great 5.56 setup.

YMMV of course

That's the best, most concise summary I've seen for this round so far. I think this or something like it should get a sticky.

[Matt-man]

There are a few mini .223 length actions out there, I've seen some pretty neat 7.62X39 bolt guns before that were very handy.

The CZ 527, Browning super-short A-Bolt, and Charles Daly mini-Mauser are all .223-length bolt actions. I'd want an AR in 300 BLK first, but I sure wouldn't mind having a scaled-down bolt gun too.

[Altair]

I think the 300BLK has tremendous potential within its design parameters. It is highly efficient in short barrels and is very effective suppressed. It isn't and will not be a long range cartridge.

I'm currently loading the 110gr V-Max at 2150fps and the 110gr TAC-X SBR at 2100fps in my 10.5" Noveske barreled AR SBR. The 110gr V-Max performs similarly to an expanding soft point at or under 2100 fps so it performs surprisingly well. The 110gr TAC-X SBR was developed by Barnes specifically for reduced velocities and expands much better than their standard 110gr TAC-X/TSX at 300 BLK velocities and still provides good penetration. It should perform well against barriers as most of the Barnes line does with the exception of windshield glass, which seems to be a problem for the all copper bullets for some reason.

I'm sure you've noticed there's alot of "should" and "similarly" and the like in my post and it is because, as Jason pointed out, the round is just being developed. It needs alot more testing but I think it really shows promise.

The main advantage for me was the versatility to go from supersonics to suppressed subs. The 300BLK takes the cake in this regard and really makes a nice quiet suppressed carbine. Outlaw State Bullets has developed a 220gr expanding subsonic bullet designed to cycle in AR's which is very promising as well but I have not yet tested them.

If you are interested only in supersonic you might look at the 7.62x40. It shares the same efficiency in short barrels but can best the 300BLK is max velocity. I have one of both and prefer the 7.62x40 for supersonics but it simply can't compete with the 300BLK for versatility with subsonics. It also doesn't have the level of support the 300BLK does so you only have one source for brass and ammo, but it is easily formed from .223 and reloaded.

[702Shooter]

Great thread. Thank you.

[Rwatts62081]

I am building a 300BLK M4A1(ish) carbine. Im going with a 14.5" black hole weaponry barrel. Which twist would be best? The 1x8.5 or the 1x11 twist. I will be using supersonic loads.

[snackgunner]

Thought I would ask this here rather than make a new thread.

Does anyone know the weight difference between the 300blk and 5.56 round?

Or say for example, whats the weight difference between a 30rd PMAG filled with 300blk rounds compared to a 30rd PMAG with 5.56 rounds?

Curious to know for gear loadout purposes.

[rsilvers]

125 - 62 is 63.

63 * 30 is 1890.

So that is 4.25 oz difference in bullet weight. But the brass is shorter. So probably about 3oz difference.