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300 Blackout

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hminsky

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300 AAC Blackout, why not?

I've been reading about the 300 AAC Blackout cartridge. It seems cool because it's .30 caliber (seems more versatile than 5.56 if you ever wanted to hunt something larger than a coyote) and it uses existing AR15 5.56 magazines and bolt/carrier group. The magazines even have the same capacity as they do when using 5.56.

I see the ammo selling as low as .80 a round.

I saw a stainless steel 16" upper in 300 BLK for $320, not much more than a .22 conversion kit.

So what's not to like?
 
My very basic knowledge of 300 AAC Blackout is that it was designed to be used with subsonic loads and a suppressor -- not that you can't go supersonic with it. I'm not sure if 300 AAC Blackout was really designed for hunting game, unless you need to unload on a den of wolves or something.
 
Subbing in for more info. I have wondered about this myself, but haven't seen much discussion about it. Hopefully someone here has experience in this caliber.
 
I want one when I get to NH and can free-man-it-up with a can. It is cool, but I am not sure it does anything much better then 5.56, except run out of gas quicker.
 
Its apparently the ideal sub 300 yard sbr cartridge with supersonic loads, and the subsonic loads are great for a can, although I'm not sure how it differs ballistically from .45 at those speeds.

Mike

Sent from my SAMSUNG-SGH-I727 using Tapatalk 2
 
Great article in this month's American Rifleman on the Blackout and the Whisper which should answer a lot of questions. If you hunt , want to shoot an AR in USPSA competition and make the major power factor, or need a subsonic round for your suppressor, these calibers might be for you.

Why not? Cost. 223 can be had for about .30/round if you buy in bulk. Why spend more? Speaking of uppers, I do most of my shooting with a dedicated 22 rimfire upper. As long as you stay within 75 yds performance and point of impact are very similar to 223. The last lot of 22 Blazers I bought cost me $.03/round. Compare that to 223 at $.30/round. I have run about 20,000 rounds of 22 rimfire through my AR. Compared to 223, I saved $5000, including the cost of the 22 rimfire upper and not including the cost of a barrel that the 223 would most likely have worn out. The savings are huge.
 
How come I never see all the free staters with cans on their rifles at MRGCI? Are they hard to get?

-tapatalk and Devin McCourty blow chunks-
 
I own .300 Blackout. I have the 16 inch barrel with no suppressor. When I first built the rifle, I purchased PNW ammo in 147 grain. The barrel (SI Defense in 1/8 twist) is tuned for only supersonic from the factory. In order to cycle subsonic you would need to open up the gas hole on the barrel to cycle subsonic properly. At first, the rifle had an issue cycling the supersonic rounds. I thought 147grn rounds were too "subsonic" but the issue was I misaligned the gas port and hole. Because of that issue, I purchased some 115grn Remington rounds thinking it was the ammo, not the misalignment. Now this rifle works beautifully with both grains. There is a little more recoil compared to 5.56 but less than .308 . Also, the round is A LOT louder that 5.56. To me, it sounds a lot like a .308 AR, at least using supersonic ammo. I have been waiting till after Christmas to purchase a suppressor for it to test the Decibels of the rounds both super- and subsonic.
The video is correct about a lot of the attributes of the round and the interchangeability of 5.56 ARs and .300 Blackout ARs. Both my metal and PMags fit the round right to a 30 count. Of course, this shouldn't be a total surprise seeing that the .300 brass is essentially 5.56 brass cut and the neck re sized for the larger bullet. Because of this, the bolt is the same. No need for a specialized bolt like many other wildcats. Here is a few pictures of the brass and rifle.
DSC00318.jpg DSC00321.jpg
There are a couple of disadvantages to this wildcat, though. One is the availability of ammo for it. Unless you reload, finding it can be a chore. All the shops I have been to don't carry it, making you purchase the ammo online or reloading ammo yourself. Another disadvantage is the "rainbowing" of the round. This round is definitely not a long range shooter. Unfortunately, I have only shot it out to 100 yards with no real bullet drop. However, many articles online have showed that bullet drop can become significant past two hundred yards.
Ultimately, I like the round but hate having to search and wait for ammo. It is a nice difference from a standard AR without breaking your wallet over the price of the rifle, like an AR 10 will. Combined with the ex changeability of parts to the 5.56 AR and the extra "ommpf" from the round, I enjoy shooting it.
Here is a link to more information about the round and the rifles with and without suppressors.
http://300aacblackout.com/resources/300-BLK.pdf
 
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I'm with Hickock45. I was interested in a .30cal AR and was turned off by the complexity of 7.62x39 conversions.

At first I was under the impression 300BLK was subsonic only so I dismissed it, but that's just not true. There are a number of different rounds currently being made. After looking into the rounds capabilities and noticing with great joy that the only non-standard part you need to build one is the barrel, I bought a barrel and built myself an upper. I haven't shot it yet for lack of ammo. I've been having a lot of trouble finding cheap range-quality ammo for this gun. Most of what is actually available seems to be the fancy nosler-tipped hunting rounds which are really expensive.

I just bought 500rnds of 147gr range ammo for $275 from getontargetammo.com (to clarify, I had it shipped to an FFL. they DO NOT ship to MA residences) and I figure I'll reload those cases. 2000fps at the muzzle, and supposedly very similar ballistics to 7.62x39. 30cal AR15 battle rifle with 100% interchangeable parts save the barrel. How can you resist?
 
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mr_hao said:
if you like 300 blackout then check out 300 whisper
Click to expand...

They are basically the same cartridge with a different name.

I checked out the .300 AAC/blackout/whisper and built a 6.8 SPC. The terminal ballistics on the 6.8 SPC were much better than the 300 for supersonic rounds.

For subsonic work, the larger .30 caliber may be better. What are you going to be using it for? If for deer hunting, go with the 6.8 SPC.

A 125 grain .300 AAC bullet has a muzzle velocity of 2250 ft/s and energy of 1360 ft-lbs. A 115 grain 6.8 SPC has a muzzle velocity of 2575 ft/s and an energy of 1694 ft-lbs. 300 additional ft-lbs of energy is significant IMO.

With the 6.8 SPC you can go with lighter bullets (85 grain) and get a muzzle velocity of 3000 ft/s and muzzle energy of 1700+ ft/lbs.

So, depending on what you want to do, the 6.8 SPC may be a better choice.

If you want a .30 caliber, I would go with an AR-10 or LR-308. Old mil-spec .308 ammo is as cheap or cheaper than the 80 cents per rounds and you get way more energy with the .308 round. Cost to build, increases, however.
 
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I think it started out as a .30 round that would fit in existing USGI mags, bit it is marketed to people with cans. There are suppressor and standard loads available.

hminsky said:
I've been reading about the 300 AAC Blackout cartridge. It seems cool because it's .30 caliber (seems more versatile than 5.56 if you ever wanted to hunt something larger than a coyote) and it uses existing AR15 5.56 magazines and bolt/carrier group. The magazines even have the same capacity as they do when using 5.56.

I see the ammo selling as low as .80 a round.

I saw a stainless steel 16" upper in 300 BLK for $320, not much more than a .22 conversion kit.

So what's not to like?
Click to expand...



Sent from my Galaxy Nexus using Tapatalk 2
 
I belive S&W's 300 Black out upper also can shoot 300 Whisper. For all i Know they all can. I too am just starting to learn about this cartridge.
 
Baystatesuks said:
They are basically the same cartridge with a different name.

I checked out the .300 AAC/blackout/whisper and built a 6.8 SPC. The terminal ballistics on the 6.8 SPC were much better than the 300 for supersonic rounds.

For subsonic work, the larger .30 caliber may be better. What are you going to be using it for? If for deer hunting, go with the 6.8 SPC.

A 125 grain .300 AAC bullet has a muzzle velocity of 2250 ft/s and energy of 1360 ft-lbs. A 115 grain 6.8 SPC has a muzzle velocity of 2575 ft/s and an energy of 1694 ft-lbs. 300 additional ft-lbs of energy is significant IMO.

With the 6.8 SPC you can go with lighter bullets (85 grain) and get a muzzle velocity of 3000 ft/s and muzzle energy of 1700+ ft/lbs.

So, depending on what you want to do, the 6.8 SPC may be a better choice.

If you want a .30 caliber, I would go with an AR-10 or LR-308. Old mil-spec .308 ammo is as cheap or cheaper than the 80 cents per rounds and you get way more energy with the .308 round. Cost to build, increases, however.
Click to expand...

stinx said:
I belive S&W's 300 Black out upper also can shoot 300 Whisper. For all i Know they all can. I too am just starting to learn about this cartridge.
Click to expand...

Yes they're the basically the same that's why I said to check it out lol. I think overall 6.8 is a better round, how many people can say they'll put a can on their rifles anyawys? Which is where the 300 blackout would shine.
 
hminsky said:
I've been reading about the 300 AAC Blackout cartridge. It seems cool because it's .30 caliber (seems more versatile than 5.56 if you ever wanted to hunt something larger than a coyote) and it uses existing AR15 5.56 magazines and bolt/carrier group. The magazines even have the same capacity as they do when using 5.56.

I see the ammo selling as low as .80 a round.

I saw a stainless steel 16" upper in 300 BLK for $320, not much more than a .22 conversion kit.

So what's not to like?
Click to expand...


It's an under-powered round designed for use with a suppressor. If you're not going to run it suppressed, there are much better options.

If you want a better hunting round for use in an AR-15, something in 6mm would probably be "best," although 6.5 or 6.8 would also be better than 7.62. There's just not enough case capacity to drive the bigger calibers fast enough.

If you want a hard-hitting caliber that you can shoot out of an AR-15 and that's legal for hunting in most if not all states that allow rifles, check out the .240 Tomahawk. (Or even the 6x45 if you want to use 5.56 brass.)
 
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Just curious. Why did the make 300AAC shorter overall than 5.56? It seems they could have kept the same overall length and that would have allowed more powder.
 
PaulD said:
Just curious. Why did the make 300AAC shorter overall than 5.56? It seems they could have kept the same overall length and that would have allowed more powder.
Click to expand...

As far as I know they have the same official OAL. (2.26" to fit into an AR mag.)
 
jasons said:
As far as I know they have the same official OAL. (2.26" to fit into an AR mag.)
Click to expand...

Sorry, you're right. In the video, Hickock showed a round that was shorter but it seems it was because of the light bullet. Max OAL is the same.
 
jasons said:
It's an under-powered round designed for use with a suppressor. If you're not going to run it suppressed, there are much better options.

If you want a better hunting round for use in an AR-15, something in 6mm would probably be "best," although 6.5 or 6.8 would also be better than 7.62. There's just not enough case capacity to drive the bigger calibers fast enough.

If you want a hard-hitting caliber that you can shoot out of an AR-15 and that's legal for hunting in most if not all states that allow rifles, check out the .240 Tomahawk. (Or even the 6x45 if you want to use 5.56 brass.)
Click to expand...

There are definitely better rounds for the AR platform for hunting but the .300 blackout is great for multiple reasons. Sure it sucks that in MA we can't get the suppressors to make the .300 uber-cool but it's still fun.

1. Emulates ballistics of 7.62x39
2. Uses existing AR magazines with no loss of capacity over 5.56
3. Uses same AR internals except for the barrel
4. Commercial big-company support. 6.8 has remington backing it but it hasn't really taken off commercially in part due to #2 & #3. 6.5 is a great caliber but the ammo is expensive and very hard to get if you don't handload especially here in MA where we can't have it shipped in.

I'll bring my 9" AAC .330BLK SBR to the club one night and we'll see if we can change your mind :)
 

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