.300 AAC Blackout SBR

After the Royal Rangers lock-in I went shooting with a couple guys from church. Both are brothers. The older one Thaddeus had a home made Short-barrel-rifle chambered in .300 AAC Blackout. I was quite impressed with how that round was much quieter than the typical .223 from a carbine sized barrel. The AR-15 Luke shot gave me vibrations in my teeth but the .300 blkout didn't.

I'm considering building an upper receiving and making an SBR.

Claymore what has your experiences been like with the .300 blackout round?

When they were coming in, I was in my last couple of years of Law Enforcement, and far-removed from my days in Special Ops.

It seems to have kind-of a cult following.  It looks like it has the best applications if you want to run it with a legal "can" on the end of your barrel.  But when you go with the subsonic load, shot-placement becomes pretty critical (just like that 147 grain 9mm load).

If you want something that is "quieter", then the .300 B/O might be fun, but it only has about the energy of a .223 (about 1,350 Foot/Pounds: 1,280 for the .223).   With the subsonic bullet, it will probably also have a trajectory that falls on the same ballistics chart as a rock being thrown by a 7th grade girl.

If you're looking for something to play with that has a little more "thump", then the 6.8 SPC puts you into the 1,650 to 1,785 Foot/Pounds vicinity.

Is the .300 whisper the subsonic version of .300 aac blackout?

With .300 aac blackout having the same energy as .223 but in the .30 cal range would it be appropriate in hunting big game?

His bro has a suppresor (legal can) but wasn't using it that day and was using regular ammo not subsonic with a NFA short barrel.

From "Thetruthaboutguns":


  Nick

   300 AAC Blackout and 300 Whisper ™ are not the exact same thing. It is similar to .223 vs 5.56mm in that the difference is in the neck of the cartridge.

   300 AAC Blackout is SAAMI spec cartridge whose origins come off the 5.56mm case and cartridge case drawings and chamber drawings are available from SAAMI for the round and in fact are available to anyone right on line.

   300 Whisper ™ is a Wildcat cartridge based on the 221 Fireball case and there is limited information out to the public or manufacturers in the way of cartridge drawings or chamber drawings. 300 Whisper ™ has traditionally been a round oriented toward handloaders and there is a lot of reverse engineering done out in the marketplace. There is not a published “Standard” for 300 Whisper ™ chambers and cartridges. As such, we cannot tell customers that you can shoot 300 AAC Blackout ammunition in a 300 Whisper ™ chambered firearm, or that you can shoot 300 Whisper ™ ammunition is a 300 AAC Blackout chambered firearm.

   Our recommendation is that if a consumer want to cross ammunition and chambers with these two caliber, that they have the ammunition and firearm checked by a qualified Gunsmith to assure it can be done safely.

   Thanks,
   John Hollister | Sales Manager
   Advanced Armament Corp.

Thanks for info. I was sure cause I thought I had see. The two advertised before for a single rifle.

What's your opinion on it being used for hunting?

RRCmdrBennett wrote:

With .300 aac blackout having the same energy as .223 but in the .30 cal range would it be appropriate in hunting big game?  

In my opinion, absolutely not (but you may hear differently on the Web).

The strength of the .223/5.56 has always been a projectile traveling between 2,800 and 3,300 Feet Per Second.  That much energy striking a target that is 90% water (animals) is what causes the devastating damage.

So, especially with the heavier bullets, you're hunting with something in the class of a .45 Auto Pistol.  Now who would hunt big game with that?

Now a lot of poachers have taken deer with a .22LR, but I wouldn't personally do that, either.

Would you recommend the 6.8 spc for hunting?

MOST 30-30 ammunition runs between 1,600 and 1,900 Foot/Pounds of Muzzle Energy. The 6.8 SPC falls right in the middle of that range. So if you think that a 30-30 is appropriate for hunting, then a 6.8 should be, also.

Where I am, the subspecies of Whitetail Deer is the Virginia, or Southeastern, Whitetail. A deer here over 100 pounds is considered as big. Although I trailed for two days (and lost) a doe that I had shot with a .223 here, I think that a 6.8 would have been more than adequate.

I think that you are within the range of the Northern Woodland Whitetail. Big Bucks of that subspecies can reach 200 or 225 pounds. I've hit a Northern Buck with a well-placed 12 Gauge Slug at 40 yards, and he still jumped a fence and went another 150 yards. So a 6.8 might be on the border (as may be a 30-30) for a big buck like that.

Unfortunately, Ohio only allows straight walled cartridge rifles to be used during deer season no conical style. I don't suppose there are any straight walled cartridge upper AR receivers?

Sounds like you just need to go hang out with uncle Claymore one weekend and hunt some of those Mississippi deer with a caliber of your choosing!

But Philip Claymore only has two guns...!

I meant you could bring one of yours. I'm already offering his couch to you. I don't want to overreach by offering a gun too!

So you want a straight-walled cartridge to run through your AR-15?

Here you go:

https://en.wikipedia.org/wiki/.50_Beowulf

A straight-walled cartridge designed for the AR-15 with 2,338 Foot/Pounds of Love out the Muzzle.

Philip, you said caliber of my choosing. I think Claymore's two guns come in almost all calibers.

Claymore, have you used the Beowulf caliber before for hunting? For Ohio the last years they allow straight walled cartridge rifles.

I looked on the website, but couldn't find prices. I'm betting they're pretty expensive.

Phillip Gross wrote:I looked on the website, but couldn't find prices. I'm betting they're pretty expensive.

What site the wiki?

At the bottom of wiki it has a link to the actual website.

RRCmdrBennett wrote:Philip, you said caliber of my choosing. I think Claymore's two guns come in almost all calibers.

Claymore, have you used the Beowulf caliber before for hunting?  For Ohio the last years they allow straight walled cartridge rifles.

No. The only "exotic" caliber that I have used in an AR-15 is 6.8 SPC.



Insofar as your later question; "expensive", depends on your point of view.

Upper Receivers start at around $650.00 to $695.00.

Complete Rifles start at about $975.00.

Loaded ammunition runs about $50.00 per box.

Those prices for the .50 Beowulf?  Do the uppers include the barrel, D ring, forend, gas block, flash suppressor, barrel, bolt carrier and charging handle?

Not bad I paid $750 for the Windham and when I had the M&P15 it was $879.

I like this one http://www.gunbroker.com/Auction/ViewItem.aspx?Item=520026963

Cabela's has one new for $779 complete upper.

At first, I was wondering why the seller on Gunbroker was getting rid of it, but I see that it is a business with over 3,000 previous sales.

Mid-Length Gas System is nice. More reliable than the Carbine Gas System, and easier on your Upper Receiver/Bolt Carrier Group.

This article I came across promotes the .300 blk for deer hunting like you said the web might claim different and gives details on just swapping out the barrel instead of buying a complete upper.

Would you swap out the barrel or always use a complete new upper?  I never knew you could switch calibers without using a whole new upper assembly.  I don't suppose I can just swap out my 5.56mm barrel for .50 Beowulf?

You can't really just "change barrels" on an AR-15. It's not like a Thompson Center Contender or a Handi-Rifle.  Someone may be mixing the terms "Change Barrels" with "Change Uppers".

In order to "Change Barrels", you have to remove the handguard assemblies, drift out the Gas Tube Pin, remove the Gas Tube, put the upper in a special vice fixture, unscrew the barrel nut, then put in the new barrel, torque it to specs, put in the Gas Tube (a considerable amount of "monkeying" may be required to insure that it is not striking the Gas Key in the Bolt Carrier), then set the new Gas Tube Pin and Handguards.  Of course, your barrel and front sight are no longer aligned as the previous one was, so you must now take it to the range to re-zero it.

Also, if you are going from 5.56 to 'most anything else, you must also change the Bolt Face because of the different Rim Diameter of the new Caliber.

Oh, then you had better get your set of Headspace Gauges to insure that the Bolt Face and Barrel mate up within SAAMI Specifications.

There may be some people who will say that changing barrels on an AR-15 is a half-hour job.  For me, it generally consumed the better part of an evening.

Now, besides that, a stripped Upper Receiver only runs about $125.00.  By the time that I had switched out the Barrels/Bolts/etc two or three times, I would have exceeded that in aggravation.

Wouldn't you rather have a complete upper (all sighted in for a particular load) that you can just pop onto your Lower Receiver?   That way, you can plink, practice, or shoot competition with your low-cost 5.56, then be all ready to switch out for hunting without needing to do a complete Function Check and Re-Zero prior to taking it into the Field.

Besides that, if you routinely start changing Barrel Assemblies, you will definitely see accelerated wear from punching out drift-pins and screwing/torquing the barrel.  Also, different Bolt Carrier Groups can ride differently in the upper receiver, thereby causing different wear patterns inside.

Just from drifting out pins to change Hammer/Trigger Groups in my AR-15's, I have some little extra bugger marks in the finish of the rifle.

Lastly, if you build a "Frankenstein" gun and it does not reliably function, you are stuck.  You do not know what piece is responsible.  Is it a bad Gas Port on the Barrel?  Gas Tube?  Bolt Locking Lugs?

If you buy an entire Upper, it is supposed to have been built to Spec and Tested.  If it doesn't work, send it back and demand that it be made to work or be replaced.

Whatcha gonna do with your "Frankengun" if it does not work?

("It's.............ALIVE!" Gene Wilder 1974.)