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300 blackout vs 6.8

151K views 432 replies 57 participants last post by  68WJ 
#1 ·
Ok, I don't really see why everyone is so excited about the blackout. My 16 inch 6.8 with Speer 130 hotcors should be superior in the bigger, slower bullet train of thought that is giving the Blackout people a woody. Is it just because of 223 mags and bolts?
 
#2 ·
I agree with you that when you're talking supersonic performance, I just can't see the blackout having the performance the glossy ad marketing types are bragging about. I'm waiting to see how the factory supersonic ammunition velocity numbers turn out in the real world.

The low case capacity limits the performance compared to the 6.8 which is a more versatile cartridge.
 
#6 ·
I actually do have both.

The 300 BLK is a 300 Whisper or 300/221 with a slightly looser chamber and a 0.090" longer throat which helps to reduce pressure ... not unlike the difference between 6.8 SPC and 6.8 SPC II.

I too don't see the reason for the hype.

I got into the Whisper first with the intent to run a can for shorter range hunting piggies at night. Will be fun for that. Really is a shorter range relatively quiet chambering and is thus a rather specialized tool.

The 6.8 has much better ballistics at range and is big enough to make the AR platform very useful for general hunting. Is what the 5.56 should have been ;-)

If I had to give one up ... it would be the .300 BLK. Fortunately, I don't.
 
#7 ·
I think i read that the 300 has 9% more muzzle energy than the 6.8 SPC, but that is with a 9" barrel. What good is a 9" barrel? They don't really talk about that with the 16" barrel, the 6.8 has more energy than the 300 blackout. Plus with a 9" barrel wouldn't there be a lot of muzzle blast? I don't think i could stand it. With all that being said, a 30 caliber AR-15 is definitely appealing. but i think i would rather have the 30 remington than a 300 blackout.
 
#8 ·
But the .300 blk is "Tacti-cool" and the 6.8 has a funny name...so the 300 blk must be superior in every way.

kidding aside, the 300 blk looks like alot fun in a SBR with a can... But the 338 spectre uses 6.8 bolt and mags ...so if i was gonna go that route I would go with the spectre anyway. Since i don't own a 223, nor do I plan on getting one.

I tried to get excited about the 300 blk, but all the numbers i keep seeing from it are pretty anemic. At least for supersonic use.
 
#12 ·
I thought about the 300 as a home defense round with frangible varmint style bullets.

There are good bullets for the 6.8 in this role too, like the Hornady VMAX and the 90 TNT.

H, so the 5.56 mags need tweaking? To the point of needing dedicated mags? That won't help the blackout.
 
#13 · (Edited)
I meant 'close quarters' for the words 'door knocker'. Anyhow, I was just thinking more about the uses for that specific cartridge. Not so much in relation to other cartridges. Yes, home defense would be another. I'm not sure of other uses.
The problem with fragmentation rounds is intermediate barriers, from my understanding. But, I could be wrong.
 
#20 ·
'sactly H. That said - as I posted above, it would not be difficult for an enterprising person to build a couple tools to trim the rib out of PMAG's or crush the rib in USGI (at least the Al ones) mags for folks that want to hand load to a mag length round.

One could either process and sell mags (and take on the CS issues of mags that don't work so well that may have nothing to do with the modification) or figure out how to make the tools cheaply enough to sell them to folks that want to DIY.

I'd guess there might be a market for the DIY tool route - look at upper receiver lapping tools, MOACKS, chamber reamers, etc - specialty, low use tools that enthusiasts buy at some sustainable level all the time.

You know where to send my commission check ... :a26:

Mark
 
#21 ·
Since LE engagements and Home Defense engagements are well under 100 yards, it makes for a good round in those cases, especially if they could come out with some affordable ammo. Still don't understand how they screwed it up and I don't underhand why the extra long chamber. I was told the accuracy was around 3" from the sub ammo.
 
#24 ·
Since LE engagements and Home Defense engagements are well under 100 yards, it makes for a good round in those cases, especially if they could come out with some affordable ammo. Still don't understand how they screwed it up and I don't underhand why the extra long chamber. I was told the accuracy was around 3" from the sub ammo.
That's the role I see the BO being the most useful for. I'm waiting to see how the loads chrono with the hunting ammunition. I suspect they've created something less than a 30/30 which will cause me to yawn.

When they start talking of the BO as a multirole rifle better than a 7.62x39, I get suspicious and say "show me".

The 6.8 and 6.5 really changed AR performance in the multirole department. Their performance is documented. The hype on the BO has raised expectations and that could be a problem if the performance doesn't live up to the ads and forum announcements.

Part of me is still kind of interested in the BO, especially with suppressors. I just need to see things shake out on the cartridge before I'll seriously consider it.
 
#22 ·
Scraping the inside of a PMAG seems to be a better solution for the mags because only a little material is removed. Has anyone crushed the ribs on an aluminum mag? I would be concerned about the functional dimensions remaining in the aluminum magazine after the rib has been flattened. Aluminum doesn't have the memory that steel has so flattening the rib can be done, but you have to avoid changing the dimensions of the magazine while flattening the rib.
 
#28 · (Edited)
Scraping the inside of a PMAG seems to be a better solution for the mags because only a little material is removed. Has anyone crushed the ribs on an aluminum mag? I would be concerned about the functional dimensions remaining in the aluminum magazine after the rib has been flattened. Aluminum doesn't have the memory that steel has so flattening the rib can be done, but you have to avoid changing the dimensions of the magazine while flattening the rib.
Haven't tried it - but I imagine it wouldn't be too hard. A tool would need to have two (or more likely three) parts ... a clam shell that the mag goes into to hold the mag and support it externally (perhaps two Delrin blocks trapping it lightly and supporting it over its full length in a vice), and a forming tool that gets forced into the mag to deform the rib to the proper depth.

A similar tool for a PMAG would have sharp cutting edges on the leading edge of the forming tool that would remove enough of the rib. A much more elegant uniform solution than figuring out how to reach inside and scrape and hack up the inside of a PMAG along its entire length.
 
#23 ·
If I ever decide to build an AR-Pistol, I will probably look very closely at the BLK. For a non-SBR'd rifle, I will stick with 6.8.
 
#25 ·
If I ever decide to build an AR-Pistol, I will probably look very closely at the BLK. For a non-SBR'd rifle, I will stick with 6.8.
Good post. I agree. The AR pistol would be interesting. Okay, that's something I really wasn't thinking of. I was thinking a multirole rifle like the 6.8 or 6.5 is. In an AR pistol, the BO is definitely a cartridge to consider. Maybe I need to buy a Spike's pistol marked lower now.
 
#29 · (Edited)
You guys have brought up a lot of good points (pro and con).

I admit that I was on the fence for a while between the 300 black whisper and the 6.8, but I finally sided on the 6.8

I could go on for far too long about my reasoning why I did, but it would be easier and much faster to say why I didn't.

#1
Ammo availability of the 300 is virtually nonexistant right now. That's not good for anyone who doesn't hand load. I'm sure that will change later, but until then...

#2
I loved the ability the 300 had to be super or subsonic, but I admit that the subsonic capabilities enticed me much more because I am a suppressor buff.

In the end, I can buy corbon subsonic 6.8 ammo, and will still have a superior supersonic round with the 6.8

#3
I did NOT like how they compared the blackout (a rifle cartridge) to the MP5SD (that fires a pistol cartridge).

*Maybe they would have better luck with comparing APPLES and ORANGES. They're at least both kind of round.:a43: Really, how do you keep a straight face when reading shit like that? Do they think people cannot think for themselves and will just jump on the wagon because they "said" so?

And just for the record for anyone who may not know, H&K has been in the middle of planned obselescence of the MP5 series of weapons for quite some time now. Why else do you thing they're pushing the MP7 and the 416 so hard?

The BIG thing with the 300 is the subsonic area.

The military and many LE Dept's would love to have a good subsonic round they can use in their M4's to issue to their door kickers so they can better comply with OSHA standards. This is the big piece of pie that Remington/AAC wants a piece of.
 
#67 ·
I did NOT like how they compared the blackout (a rifle cartridge) to the MP5SD (that fires a pistol cartridge).

*Maybe they would have better luck with comparing APPLES and ORANGES. They're at least both kind of round.:a43: Really, how do you keep a straight face when reading shit like that?
Our military and LE customers may want to replace their MP5-SD with it. The MP5-SD is the gold standard in suppressed weaponry. If it can be replaced with something about the same size, just as quiet, but with rifle-like accuracy and penetration, that is a no-brainer.
 
#30 ·
Guys,

The Whisper-like chamberings are for NOT battle rifles! They just do not have the range. They make very much less noise than the 5.56 and 6.8 even when not suppressed!!! When suppressed they can be quite quiet.

The civilian use of the 300 BLK really is for short range hunting (150 yards or less) or as a replacement for a 9mm carbine.Is a very specialized tool that adds a different dimension of utility to the AR platform.

You want to play in that area? Is up to you. Does it put much pressure on the 5.56 or (especially) the 6.8? I don't think so!!!
 
#31 ·
Where is the battle rifle reference in this thread? Uh huh. Tell that to Fremingtonaac. They're the ones making the comparisons. They're the ones making the supersonic performance comparisons to 6.8 and 7.62x39. They're the ones who are now loading their ammo shorter limiting powder capacity, and using a throat too long so 3" groups are expected. Their advertising hype and forum bragging is coming up short.

I wouldn't be bragging about a 150 yard hunting range either. My muzzle loader does that. And a supersonic load 300 BO will still be pretty loud no matter what you're comparing it to.

A reliable sub load for LE and civilian use is a plus, but they shouldn't be tossing out all the hype about it's lackluster supersonic performance. I do see a 300 BO (body odor or blackout, your choice) being a decent AR pistol round though besides the obvious suppressed SBR. It'd make a nice PDW, if someone ever makes dedicated ammo and bullets for the low velocities.

That leads me to ask this.... would 30/30 bullets work in the BO? I mean 30/30 bullets are meant for slow speed performance. Let's load up some Hornady 30/30 Leverevolution bullets in the BO and call it a day. Maybe some round nose soft points too. Maybe we can just put a lever on 300 BO rifles in case there are any cycling issues with so little powder capacity in the case.

I would build a AR pistol in this caliber, or buy one for a suppressed rifle. That is if ammo becomes available. I'm interested in it, just watching the hype fall apart in discovery. Bill Wilson's version may turn out as a better options. We'll see.
 
#69 ·
I wouldn't be bragging about a 150 yard hunting range either. My muzzle loader does that.
Your muzzle loader does not have 30 round capacity and doubling as a home-defense weapon.

Let me ask this... would you shoot a deer at 10 feet with a 158 grain 357 Magnum revolver?

Federal rates their 357 Magnum ammo (C357E) at 539 ft-lbs at the muzzle (handgun). 300 AAC BLACKOUT matches that at 380 yards.
 
#32 ·
Silvers said the Military asked for this round, don't know who in the military and haven't seen any solicitations.
Art with SSA said a foreign country wanted to replace their MP5s and was looking at the 6.8 a few years ago. I think the 300 would be an improvement over the 9mm but if the mil had said give us a cartridge that uses 5.56 bolts and mags so all they had to do was change the barrel I think the 300 missed the mark at least for accuracy and mag compatability until they redesign the chamber so it works with supersonic loads.
 
#33 · (Edited)
I've been watching the 300 BO with great interest.

I've had a 300/221 FB for some time now. I've never had any feed problems while seating the bullets at max magazine length. Nor has my buddy. We bought our uppers on the same day from M1S. His has always been much more accurate than mine, he seems to average about 1 moa. His favorite bullet is the 110 VMax. Mine is the M118LR bullet seated to 2.26 inch OAL, mostly because I have a large supply of them. I've also used the 240g SMK seated as long as I could make it. Maybe we're both just lucky... I don't know. Anyway they all seem to feed just fine from unmodified magazines. Neither one of us use PMags.
 
#34 ·
AAC had them at the shot show. We looked at them real hard. We came to the same conclusion that you guys did. The 6.8 outperforms it except in the subsonic field. The problem with subsonic is you have a hole puncher with no expansion. And try to find ammo good luck. We were talking to SSA they are coming out with more 6.8MM rounds. They are also coming out with an inexpensive plinking round. We have been loading for some time, and the barnes have really got some good projectiles out. With the 11.5 SBR shooting the 95gr triple shock we are averaging 2550 FPS. I also talked to the boys at POF, they are currently working on a .40 and .45 upper in a gas piston system configuration. They hope to have that out later this year. For a 9" upper that 40 or 45 would be a hell of a knock down machine.

My Daughters latest video with the 11" 6.8MM!
 
#35 ·
Cool video, wish I had a POF 6.8 SBR when I was her age. Actually I'd like to have the POF now!

We'll just have to do a wait and see on the 300 BO. Bill Wilson's project sounds interesting as well. You really caught my attention with POF bringing a 40 and 45 upper to the market. I have both calibers in handguns, and a carbine for defensive work in either sounds promising. I did not know that project was in the works.
 
#38 ·
Well I jumped into a 300 BLK, but I did it know full well that I am doing it for sub-sonic use only.
For me its a super quiet sub gun. I didn't do it to replace either of my 6.8 rifles because there is
no way it could do that. I love my 6.8's and I don't even see them in the same category as the
300 BLK. For me the 300 is going to be a fun little plinker for short range quiet use only. If I had
to choose a single gun to carry, it would always be one of my 6.8 rifles, but luckily I don't have to
choose.......

MY 300 BLK w/ 10" Noveske
 
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