Home Forums Hunting & Shooting Ask The Gunwriters 300 AAC BLACKOUT.....6.8SPC all over again?

Some information to study.

300 Blackout Technical Data




For me, that leaves ANY AR15 platform cartridge off the radar. I'd want a lot more juice than any of them offer.

Thank you for the link, WhelenAway. For some reason, if you google "AAC," it doesn't find this web page but only another one with their suppressors on it.

I wanted to compare the .300 Blackout with the .223 using 75 grain Hornady HPBT bullets, which are probably the most popular bullets currently used in NRA High Power competition at 200, 300, and 600 yards.

Guess what? The Hornady 75 grain .223 bullets, loaded (according to Hornady) to 2700 fps, beats out the .300 Blackout supersonic loads. Briefly, the .223 starts out at a much higher velocity with a bullet that has a better ballistic coefficient than the 110 grain Barnes or 125 grain Match. At 300 yards--sighted in at 200 yards--it is 8.9 inches low vs. 14 inches or more for the two 300 bullets. It has 707 foot pounds of energy at this distance vs. 606 and 681 respectively for the two 30 caliber bullets.

The .223 data is from an AR15 with a 20" barrel while the .300 data is from a 16 inch barrel. However, I don't think it would make much of a difference. There just isn't enough difference, in my opinion, between a .223 with good ammo and a 300 blackout to justify the latter.

Much of the .300 information seems to be aimed at military applications with short (9 inch) barrels etc. There are advantages to it there, but that is not my application.

As for calling the .300 a semi-automatic 30-30, I think the 30-30 is in an entirely different class. A 30-30 can fire much heavier bullets at higher velocities. The .300 seems midway between the old M1 Carbine round, which can shoot 110 grain bullets at 2000fps. and the 30-30, which can shoot 110 grain bullets at 2600 fps, says Hornady.

I am still unimpressed with the .300 as a hunting cartridge and will also add that I would not hunt deer with a .223 either.

You miss the point Indy. Its not supersonic that makes the Blackout so much fun, Its shooting quietly with a round that will cycle in an AR and drop deer and pigs like a stone. I am not aware of another round in AR15 format that will do that. I am saving my nickles for a sig AR in 308. I can use my same suppressor on it and the sig will cycle subsonic .308 win.

This. Quiet heavy bullets. Although I prefer mine in a bolt gun.

I drop deer with a 5.56 just fine. I kill with 62 grain TSX bullets, pass thru no problemo. Just 4 hours ago I killed a 200 pound pig with a 75 grain Scirocco 2, 1 bullet into the shoulder pig dropped on the spot, it did not exit. To each his own, but no one should have the slightest doubt that a 5.56 will not drop a deer in its tracks with a decent bullet.

Yep, and we have been killing hogs on the farm with 22 rifles for close to 100 years.

Elmer you must be a good shot with the barrel against their heads. I am sure they "drop like a stone" that way.

Maybe but look at what you give up.

According to AAC, the subsonic 200 grain SMK load, sighted at 100 yards, is 33 inches low at only 200, and over 100 inches low at 300!!. The 200 yard drop is worse than a .22 LR equally sighted.

Many varmint hunters (woodchuck in these parts) like to have a rise of only an inch. Applying that standard would give you 1" above LOS at 50 yards and 4 inches low at 100!! That's not even useful for varmints.

And what's with this 400 foot pounds of energy? The lowly .30 Carbine has 986 foot pounds at the muzzle, and doesn't drop below the .300 BO until you get out around 200 yards--if you can even hit anything with a 33 inch drop.

Penetration? It correlates with bullet momentum. The momentum is the same as a .30 carbine (half the velocity times twice the weight). That's not very much. I have seen .30 carbine bullets lodge in the target frames at 200 yards.

Here are the .300 BO objectives, according to AAC's web site. I have put my comments in capitals below each of their objectives.

Create a reliable compact 30-.‐cal solution for AR platform

I'M INTERESTED IN PERFORMANCE AND RESULTS. WHO CARES IF IT'S .30 CALIBER OR IN AN AR PLATFORM?

Utilize existing inventory magazines while retaining their full capacity

UNLESS YOU'RE THE ARMY, WHO CARES? MAGS ARE CHEAP.

Create the optimal platform for sound and flash suppressed fire

THERE'S NO SOUND SUPPRESSION UNLESS YOU LIMIT THE RANGE TO LESS THAN AN 1873 SPRINGFIELD.

Create compatible full power ammunition that matches 7.62x39 ballistics

WHY? 7.62X39 IS PRETTY CRUMMY BALLISTICS, AND I THINK "FULL POWER" MEANS 7.62X51 AT LEAST.

Work with subsonic and full power ammunition without requiring adjustable gas.

AGAIN, WHO CARES? YOUR ZEROS ARE GOING TO BE GROSSLY OFF AND HAVE TO BE ADJUSTED.

Provide the ability to penetrate barriers with high-.‐mass projectiles

EQUALS A .30 CARBINE FROM WWII.

Provide all capabilities in a lightweight, durable, low recoiling package

RECOIL, BY NEWTON'S SECOND LAW, IS ALSO IDENTICAL TO A .30 CARBINE (if the weight is the same).

Add to this the fact that heavy bullets and low velocities are frankly dangerous around populated areas because they have a much higher propensity to ricochet if fired at low angles.

You are wise to get a SIG in .308. If I were you, I'd dispense with the suppressed .308 loads and use lighter supersonic bullets. Explain to the neighbors why they're safer. If you only shoot seven deer a year, it shouldn't be any problem.

In the interest of results I submit the following

300 Whisper 40 yards


300 whisper 12 yards


44 mag 35 yards


44 mag 28 yards


Big heavy subsonic suppressed bullets work great by me and to think I never dialed 300 yard dope into the turrets.

Obviously, it works just fine . . . in the hands of a good hunter.

You mean placement matters?!?!

Obviously. But the point is---you can't always get perfect shot placement. And at least in Ohio, you can get shots on white tails at 100 yards of more. I'd much rather take the shot with a .308 or with your .44 magnum. Both of these are far superior to the .300 BO with 220 grain bullets.

Also why screw around with trying to cram everything into an AR15 platform. The .44 magnum rifle in the photo obviously didn't need a 20-shot magazine.

That's a nice chart, but too bad you left out the 6.5 Grendel (aka 264 LBC). It would show a 6.5mm 123gr Scenar started at 2400 FPS still with over 1000 ft-lb of energy at 300 yards.

I think it's a much superior round to either the 300 BO or the 6.8 Rem.

Oh and the 44 mag was loaded to subsonic velocities also. Comparable to 44 special. Again big slow bullets with no straw man worries about ricochet.

Please don't take ricochets lightly. A .22 Long Rifle bullet will ricochet where a high velocity varmint bullet from a .223 will not. It's all about bullet construction and velocity.

One of my former clubs found that bullets were ricocheting down range when fired into a backstop. We didn't think this was possible, but one of our members, who lived a good distance down range, reported bullets were hitting his property. We consulted the NRA who told us how to shore up the backstop with a lot of construction (and member assessments).

Neither the 22 LR nor a high velocity varmint bullet are under discussion here. Please cite (other than anecdotal) your assertion that a slow bullet is any more prone to ricochet than a fast bullet.

That's why if you close your eyes, you can hear the death rattle of the Grendel.

But I would take anything provided by Mr. Silvers and AAC with a grain of salt. They believe marketing and honesty are contradictions in terms. Not just in regard to the .300BO, where I've had words with Mr. Silvers on stretching the truth on several occasions, but even their suppressors.

I was considering one of their suppressors recently and was amazed that their specs showed that it only added 4 inches to the rifle.

Then I went and looked at one in person and laughed when I realized that in the world of AAC, a suppressor that requires a proprietary adapter made by them, that adds almost 4 inches to the rifle barrel, doesn't count when they claim the suppressor only adds 4 inches.

To AAC, 4+4=4.

As to the above chart. It's amazing how they chose one of the lowest BC bullets available for the 6.8spc, to compare in a 300 yard comparison.

spot on. when madness subsides I will get a 6.8SPC

I've never understood all of the "haters" whenever a "new" cartridge comes out, particularly one designed for the AR platform. The 223 is a "niche" cartridge in many areas, and minds. The 300Blk seems like an interesting cartridge for a lot of applications, the 6.8 is probably the best all around option for an AR, but if you don't like it don't buy the frikking thing and leave it at that! Unless you have some real world experience with it...

6.8spc, .300BO and the Grendel are all fun/useful cartridges and the beauty of the AR platform is you can own all 3, use one lower and spend about as much as two decent bolt actions.