Home Forums Hunting & Shooting AR and Tactical Rifles Building an AR 300 Blackout

so why the BO now? Its been around since the 70s? Or so.

Whats with no X39 instead?

I think prevailing ideology was that our next military encounter would be in the European theater or that our Asian enemy would likely be Chinese. That we would mainly use heavy weaponry. do you use of the battle rifle, the m16, would most likely be a rear zone base weapon.
I don't think that it occurred to us until we got involved in street level fighting in the Middle East that the m16 round was ineffective either from the diminutive barrel, the light bullet, or the heavy bullet moving too slow.
we had to relearn what it took the Russians up until Stalingrad to figure out, did a moderate speed heavyI small and I small light rapid firing package was a superior urban combat weapon.
so now a generation later the United States finally realizes that the mp43, the AK 47, were designed for the battle zone we are seeing today.

So with billions of dollars invested in the stoner platform, rifles, magazines, training, ect we could either trash it all and start from scratch or use what we already have and make due.
We chose the later.
Now it may come to fruition that we adopt the BO militarily.
That's the best choice financially.

whats wrong with the X 39 in the AR? Gives same same ammo, I think that would be a HUGE issue thats a BIG plus......

Incompatibility of current BCG and magazines for one.
Colt tried it and at best it was problematic.
That couple with the problem of a .310 if the chance its ever adopted. The US has been running the .308 since the krag.

I like the 300 AAC myself and i use LilGun with the Speer 125 gr TNT as my go to bullet. I just purchased two box of the Barnes 110 gr TAC-TX bullets with the Black Polmer Tips to try next deer season. I always run my 300 BLK Super Sonic. I built my 300 AAC on a Stag LH Upper.

I wanted the blackout to do a sbr and loose only minimial velocity as possible. I like the barnes bullets, but im also fixing to try the vmax and varmeggedon, since its running at such a lower velocity and bullets will be cheaper! Barnes also came out with the 120 tac-tx for enhanced penetration compared to the 110 tac-tx, but its only available in loaded ammo so far. Noveseke 8.5" barrel. I lost a hair over 200 fps by going from 16" to 8.5"! I put it together for my sons first hunting rifle, but i guess i will get a little trigger time on it, since hes only 9 months old right now! Makes for a nice light suppressed sub 200 yard hunting rifle!

nice rig.......

This. The way I see it, is why bother with trying to make the x39 work in an AR, when you can just use the 300 Blackout? I load my own ammo, and don't see any advantage to the 7.62x39. Brass is harder to find, bullets are an odd size, and it uses more powder.

That's a nice little package....

if only one could pick up 1000 rounds of FMJ 110 or 120 grain ammo for $500!

Really interesting . Nephew runs surplus in his, plus reloads running .308 bullets. Has done NOTHING at all to the upper since he picked it up. Have never seen him have any kind of failures

Plus a big more case capacity since running super never hurt.

But if the 300 is your thing, get after it. I'd never get one for super when the x39 works as well and better for super.

ringworm,


Not to be rude, however that isn't why the 300BO came about. Pretty much everything you wrote is wrong.


Every single organization that has a choice chooses the 5.56 with blind to barrier ammunition for general use. The 300 Blackout is a specialty round at this point and there is little to no push towards it replacing 5.56mm among those who know how to shoot/fight.

scottfromdallas,

The 110gr Vmax has performed well on 100-200 pound mammals including deer. I do believe that the 110gr Blacktip Barnes offers overall nearly ideal terminal performance.

IIRC the Vmax was a bit cheaper, sadly as a creature of habit I always shoot shoulders. I don't know if Vmax would be the best bullet for this.

It'll penetrate shoulders, but wouldn't be my first choice if that's what I preferred to target.

Personally, I'll keep the Blackout for my short barrels, but for a carbine, I'm going to try a 30 HRT next. 125's at 2500-2600+, instead of 2100-2200 in the Blk.

its great there are endless varieties of fun stuff to try. The BO sucks because it is only 2200 or there about FPS, it sucks because it drops like a stone, it sucks as its not bench rest accurate, it sucks as factory ammunition is expensive and there is no cheap practice ammo, it rocks because a barrel will last forever, it rocks because it takes so little powder, produces fewer dB's even in supersonic form, punches through crap pretty good, and you don't have to have special magazines or a bolt.

I'm sure that there were many detractors against switch from the 06 to the x51.
Probably twice the number against the .223 switch from the x51.
The top of the german command was completely against the 8kurtz platform.
Just a guess, but I'd bet there were some old guys with white beards who said..." Smokeless powder? Bah! Never!"
Dissention doesn't prove rightness.
We, the US military, need an urban platform that makes the most from an abbreviated trajectory.
The days of needling a 500yard gun in the hands of an individual soldier are gone.

It's not like we already tried the 30 carbine or anything...

Those who think the 5.56 is on the way out have put way too much stock in the AAC marketing.

The 300BO is a great subsonic round but very poor given the same bullet constraints as M855. Loaded with a good hunting bullet, it's marginal at best.