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Old June 6, 2012, 08:24 AM   #1
Dubler1
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300 blackout

hey guys,
Just curious as to the .300 blkout. It seems rather new and I do not know much as to the accuracy. Does barrel length matter as much as it does in a 5.56? whats its effective range? Does anyone own one? Any info would be appreciated.
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Old June 6, 2012, 11:47 AM   #2
Palmetto-Pride
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I am building one now. A few things about it.

All it takes to convert a 5.56 to 300 Blackout is a barrel change.
Uses same bolt and mags.
Barrel length is 16" or less in fact you will be hard pressed to find a 300 Blackout barrel over 16"
Most people report sub MOA or better.
Max effective range is around 450m
It has been compared to a 30-30 out of a AR.
Ballistics are suppose to surpass 7.62x39
Great suppressed with subsonic ammo.

Per AAC Website------

Quote:
Introducing the Advanced Armament Corp. 300 AAC Blackout (300BLK). This system was developed to launch 30 caliber projectiles from the AR platform without a reduction in magazine capacity and compatible with the standard bolt.

Full power 115-125 grain ammunition matches the ballistics of the 7.62x39mm AK, and eclipses 5.56mm with much higher-mass projectiles for a more dramatic effect on the target. Or choose subsonic cartridges for optimal use with a sound suppressor - 220 grain Sierra OTM (open-tip match) bullets vastly outperforms a 9mm MP5-SD in penetration and long range accuracy.

Ammo and brass prices are low - Remington 115 grain UMC ammo is $12.99 a box MSRP - and it is not bare bones. It has waterproofed primers, crimped and cannelured open-tip match bullets, and a low-drag design.

At 300 meters, 300 BLK has 16.7% more energy than 7.62x39mm. Max effective range, using M4 military standards for hit probability, is 440 meters for a 9 inch barrel, and 460 meters for a 16 inch barrel. 300 BLK from a 9 inch barrel has the same energy at the muzzle as a 14.5 inch barrel M4, and about 5% more energy at 440 meters - even though the barrel is much shorter.

For hunting - think of it as like a 30-30 but from an AR. After you are done, you can remove your 5-round magazine and put in a 30 for plinking or home defense. For ammo, Remington has you covered with the Premiere AccuTip 125 grain. Want industry-wide support? Over 60 companies have already announced or sell products.

Due to the high efficiency of the cartridge, less powder is used than 5.56mm, which results in a rifle that is a comfortable to shoot - even with a short barrel.

Reloading dies available from Forster products, Reamers and headspace gauges available from Pacific Tool and Gauge.
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Last edited by Palmetto-Pride; June 6, 2012 at 07:23 PM. Reason: Wanted to site where quote was from.
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Old June 6, 2012, 12:59 PM   #3
sonick808
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check out the 300blackout forums, i forget the exact URL, google will reveal. I've never seen such allegiance and rancor regarding cartridges than between the 300BLK and 6.5SPC / Grendel folks.
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Old June 6, 2012, 04:21 PM   #4
rsilvers
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We know that at 300 yards the bullet expands fully, even from a 9 inch barrel. So the range is at least that. I have shot a 16 inch too 600 yards and hit a 3 inch (1/2 MOA) bullseye.

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Old June 6, 2012, 06:28 PM   #5
eldorendo
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Those are some encouraging reports. I was just reading some posts over on 6.8 forum that said that the max effective range for the .300 BO was about 200 yds, and that it was way behind 6.8 & 7.62X39 in energy and had a terrible trajectory.

I do know that Gunn Ammo, in Blakely, GA, is doing a lot of load development for the .300 BO and is selling every round they can make.
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Old June 10, 2012, 05:25 AM   #6
rsilvers
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They were incorrect. I still have not figure out if they just are bad at math or are being misleading on purpose because they see the low-cost 300 BLK as a threat to 6.8 - which costs 50% more to shoot.

How can the effective range be just 200 yards when here is a photo of a fully expanded bullet at 300 yards - *** from a 9 inch barrel ***? This bullet went a full 20 inches into 10% ballistic gel.

While it starts out with less energy, the high BC bullets make it up - and the 300 BLK has 16.7% more energy than Lapua 7.62x39mm ammunition at 300 meters. It even has more energy than the 85 T-TSX in 6.8 at 200 or more yards.
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Old June 10, 2012, 08:27 AM   #7
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Thanks for that info. Yeah, I don't know what the motivation was for the guy who posted the negative info about the .300 BO, but it just didn't sound right to me. The guys @ Gunn ammo are using two Dillon trimmers for cutting back 5.56 brass for forming .300 BO. They're cutting .020" with the first cut, then another .020" on the second cut. They tried doing the full .040" with one cut, but were rapidly wearing out the cutters.
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Old June 10, 2012, 08:41 AM   #8
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Shot my new 300 Blackout yesterday put 40 rounds thru it with zero malfunctions. I used a PSA FN 16" 1-8 CHF barrel, YHM low profile gas block, AAC BLACKOUT Flash Hider 7.62MM 51T 5/8X24. I converted a S&W M&P15T to 300 AAC I never liked the 1-9 twist barrel it came with anyway.

I was getting 1.5 MOA with Gunn ammo and a little under 1 MOA with Remington Premier OTM ammo. Recoil didn't feel much different than 5.56. Overall I am very happy with it.






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Old June 10, 2012, 08:53 AM   #9
ritepath
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The 300blk has put my deer hunting AR on hold until I see if it continues to catch on.

Right now my 6.5 lower build is kicked under the bed...waiting.

I've wanted a 6.8 for a few years but "plinking" ammo just never appeared. While I want this for a hunting gun, I would like to be able to afford shooting 100 rounds when I take it to the range. Even with the low "200 yard max" that so many seem to preach I'm thinking it should do the trick. I've killed two whitetails beyond 200 yards in 29 years.

Considering it uses the same mags and bolts I already have it's a win-win IMHO.

I'm really liking the PSA offerings.
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Old June 10, 2012, 10:44 AM   #10
Palmetto-Pride
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ritepath I was in your shoes a while back. I knew I wanted to build somthing other than 5.56/223 (already had three anyway two almost the same) I was flip flopping between 6.8SPC, 6.5 Grendel and 300 AAC. I went with the 300AAC Blackout because it has a cool name.....lol.....J/K For me it was a few reasons I wanted to be able to hunt deer and hogs with it, I love the idea of shooting a 30 caliber bullet out of a AR platform and still able to use the same bolt and mags, all that's required is a barrel swap. I also have shot very few deer outside of 200 yds (although I think the 300 AAC could take a deer much longer if need be) Ammo really isn't that expensive I ordered 10 boxes of Remington UMC 300AAC ammo from Midway for $11.99/box. Sure it will probably never be as cheap as 5.56 to shoot, but its really not that bad and will probably come down as it gets more popular.

Also forgot to add that it is compatible with the 300 Whisper which Hornady and a few others make ammo for.
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Old June 11, 2012, 07:23 AM   #11
eldorendo
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If I go with .300 Blackout, I'll probably just spend a little time forming some brass from 5.56 and just shoot my reloads. After the initlal case prep, most of the reloading work would be done!
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Old June 11, 2012, 04:11 PM   #12
rsilvers
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Quote:
Originally Posted by ritepath
The 300blk has put my deer hunting AR on hold until I see if it continues to catch on.

I've wanted a 6.8 for a few years but "plinking" ammo just never appeared.
It has caught on. Ammunition is down to $10.37 a box:

http://www.cheaperthandirt.com/2AACO102860-1.html

You can't even buy 30-30 for that price.

Millions of rounds of ammo have been sold. Not 5,000 or 10,000 rounds like may be true for some other new calibers. Millions are sold and millions more ar on back order.

If you end up not liking it, you can sell the barrel and replace it with a 5.56mm barrel - and lose less than $100 in the process. The risk is so low, that if you think you want it, you might as well get it.
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Old June 11, 2012, 09:39 PM   #13
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Isn't the most desirable application for .300 BO in suppressed rifles??? That would be my primary interest in building a .300 BO rifle.
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Old June 11, 2012, 09:44 PM   #14
rsilvers
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Well I can't disagree that it is most desirable to have it with a suppressor, but it does not need one any more than 7.62x39mm or 30-30.

Regardless of if it has a suppressor or not, it is still the best way to shoot 30 cal from an AR15 if you like 30 rounds in normal magazines.
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Old June 12, 2012, 04:48 AM   #15
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Quote:
Isn't the most desirable application for .300 BO in suppressed rifles??? That would be my primary interest in building a .300 BO rifle.
Yes, but with that comes the hassle and cost of a NFA item.

Even without a suppressor its still a very desirable cartridge because you can shoot both subsonic and supersonic ammo without issue.
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