Anyone own a 300 AAC Blackout?

[Rich]

Very curious about these. Sounds like you can use a 5.56 lower and magazines.

[gunderwood]

Very curious about these. Sounds like you can use a 5.56 lower and magazines.

I do not yet, but yes you can. IMHO, this is the best non-standard military AR caliber to date. Full power loads are better than 5.56 and with great bullet options. Easy swaps to subsonic and optimized for SBRs is sweet too.

[jdonovan]

Very curious about these. Sounds like you can use a 5.56 lower and magazines.

yep have one.

yes, uses standard AR mags, bolt carrier, buffer... etc...

the _ONLY_ change is a new barrel.

Now most people aren't going to swap a barrel, so net-net it works out to just an upper swap.

If you have any other questions, fire away.

[Rich]

Sure are a lot of ammo choices available. Wonder if it is on the militarys radar?

[RWBlue01]

I have a 300-221. This is the forerunner or should I say wild cat version of the 300 Blackout.

I built it from components. Reloaded my own ammo. Tested it on gel. It is not the end all be all cartridge because companies were not producing bullets that expanded at the proper velocities when I was testing.

There is a little more to building a good 300 Blackout than just a barrel. If you are going to run subsoinc rounds, do a SBR. Get the gas port in the proper location. And get a suppressor capable of shooting the load you want.

[RocKor]

I've shot a 300 BLK AR and it shot REAL smooth, especially with the subsonic rounds. Recoil was SURPRISINGLY light.

[jdonovan]

I built it from components. Reloaded my own ammo. Tested it on gel. It is not the end all be all cartridge because companies were not producing bullets that expanded at the proper velocities when I was testing.

The projectile selection has improved vastly since the old 300 whisper days. Barnes now has 2 bullets that work great in this cartridge, 1, the 110gr was specifically tailored to work at the 2200 FPS range that the blackout can achieve.

Leigh, and others are now making heavy weight projectiles that expand, or fracture at the subsonic velocity.

There is a little more to building a good 300 Blackout than just a barrel. If you are going to run subsoinc rounds, do a SBR. Get the gas port in the proper location. And get a suppressor capable of shooting the load you want

No, for supersonic it is just a barrel change.

But I will agree that if you are going subsonic there are a number of things that you really need to do if you want good results.

Sure are a lot of ammo choices available. Wonder if it is on the militarys radar?

Nope, no one in the military could have ever heard of it.

[gunderwood]

I built it from components. Reloaded my own ammo. Tested it on gel. It is not the end all be all cartridge because companies were not producing bullets that expanded at the proper velocities when I was testing.

The projectile selection has improved vastly since the old 300 whisper days. Barnes now has 2 bullets that work great in this cartridge, 1, the 110gr was specifically tailored to work at the 2200 FPS range that the blackout can achieve.

+1 the gel tests of those Barnes bullets are impressive all things considered.

Sure are a lot of ammo choices available. Wonder if it is on the militarys radar?

Nope, no one in the military could have ever heard of it.

Of course they've heard of it, but realistically anything outside of specialized/elite units isn't going to happen any time soon. The general military is just too cost sensitive for small arms in general. Besides, many of the impressive bullets are of the expanding sort which would send the lawyers into a tizzy (it's a silly convention we never signed!). Although with things like the MK318 brown tip and M118LR they seem to be slowly justifying it away.

[RWBlue01]

Why build a 300BO, if you are not going to run it both in sub and super?

110 gr 308 bullet at 2200fps is basically a hot rod 30 cal carbine. I am not really impressed.

Come on, lets get a good expansion bullet in the 123-130gr category. It could be loaded to a slightly less than the 7.62x39 levels. It would make a decent deer cartridge.

As for the heavy subsonics that fragments or expands, what bullet, cartridge, load?

Heck, we knew how to design these bullets years ago, but no one would make them.

[gunderwood]

Why build a 300BO, if you are not going to run it both in sub and super?

That's a valid criticism. Personally, I would build one exactly because I want to run sub and super out of an "unmodified" AR platform.

110 gr 308 bullet at 2200fps is basically a hot rod 30 cal carbine. I am not really impressed.

And I'm not impressed with an AR10 (.308Win) since you can get the AR platform chambered in .338LM. So what?

Intermediate cartridges are limited by platform size/weight, desired recoil and surprise, the laws of physics haven't been revoked! If you want an AR platform with significantly reduced ammo capacity, increased recoil and weight, there are a host of large caliber options such as .450BM and .458SOCOM. .300BO is designed as competition for 5.56mm, 7.62x39, 6.8SPC, etc. The larger caliber, fancy hunting like bullets provide excellent intermediate cartridge terminal performance. Can it be matched? Sure! Same bullet launched at similar velocities is going to give similar performance. .300BO also was designed to operate within the AR platform without some of the negative trade-offs required for chamberings like 7.62x39 (which creates a really weak bolt). The cartridge design also permits easy and reliable functioning between subsonic and supersonic, suppressed or otherwise.

It's not a magic cartridge, but it is a well designed cartridge that equals other intermediate cartridges, but without some of their serious disadvantages. What makes it really interesting is the combination of features. I do agree with you about the barrel length and supersonic only loadings, but that invalidates the whole concept behind the cartridge.

Come on, lets get a good expansion bullet in the 123-130gr category. It could be loaded to a slightly less than the 7.62x39 levels. It would make a decent deer cartridge.

Have you not been paying attention?

16" barrel
300Blackout 125gr@2215fps 1360ft/lbs
7.62x39 123gr@2355fps 1515ft/lbs (Win Q3174)

Sure you can get a bit more velocity out of 7.62x39 if you shoot the hot milspec ammo rather than US commercial loadings. Guess what happens when you shorten the barrel? http://www.xcrforum.com/index.php?topic=6226.0

9" barrel
300Blackout 125gr@2030fps 1143ft/lbs
7.62x39 123gr@1904fps 990ft/lbs (Win white box...which is suppose to be Q3174, but I can't verify that)

Sure, 7.62x39 will be cheaper, but the bullet in a commercial 300BO loading will smoke the terminal performance of it. The reason those Barnes bullets are so interesting wasn't their peak terminal performance, which is rather good, but their consistency. They appear to be giving excellent results out of SBRs at all ranges out to about 300 yards. Load them in a similar cartridge and they'll do the same thing. However, ask to do that out of a SBR with reliable functioning suppressed or not and with subsonic options; not many games in town.

As for the heavy subsonics that fragments or expands, what bullet, cartridge, load?

Lehigh was referenced above. http://www.lehighbullets.com/products.asp?cat=26

Yes, it could be built but usually you had to basically build a subsonic only gun, so the interest wasn't there. (Note: .458SOCOM combined sub/super in the same platform, but was less successful IMHO because of the increased recoil and limited ammo capacity) Once you can shoot either in the same gun without mods, now that raises interest, which creates a market.

[Mindflayer]

I've thought about an upper for my AR. Then eventually a supressor... but we'll see in light of today's news.

[RWBlue01]

110 gr 308 bullet at 2200fps is basically a hot rod 30 cal carbine. I am not really impressed.

And I'm not impressed with an AR10 (.308Win) since you can get the AR platform chambered in .338LM. So what?

Then don't buy a AR-10 in 308, buy it in 338LM. Or the other chamberings that are better.

My point about the 7.62x39 vs. .300BO isn't about putting a 7.62x39 in the AR platform, it is about the bullet. The 7.62x39 bullets didn't test well at the velocities I could get from my SBR.

Then again, it is your money. Spend it however you like. I don't believe the bullets are there yet, but I do believe they will be there in a couple years IF the push for the BO continues. I have spent my money. It is what it is, but I think there needs to be more development. Until then, I have other plans and projects.

As for the heavy subsonics that fragments or expands, what bullet, cartridge, load?

Lehigh was referenced above. http://www.lehighbullets.com/products.asp?cat=26

That was not how I expected it to be done, but it has potential. How's accuracy? I have concerns about the lose fit of the .17 bullet inside the other bullet. Will they load in the 300BO in the AR magazine and feed? They are also lighter than planned. Are there results on the web for the 300BO and this bullet?

[RWBlue01]

I've thought about an upper for my AR. Then eventually a supressor... but we'll see in light of today's news.

You are doing a SBR?
Do you have a manufacturer picked out for the barrel or upper?
What suppressors are you considering?

[gunderwood]

110 gr 308 bullet at 2200fps is basically a hot rod 30 cal carbine. I am not really impressed.

And I'm not impressed with an AR10 (.308Win) since you can get the AR platform chambered in .338LM. So what?

Then don't buy a AR-10 in 308, buy it in 338LM. Or the other chamberings that are better.

My point about the 7.62x39 vs. .300BO isn't about putting a 7.62x39 in the AR platform, it is about the bullet. The 7.62x39 bullets didn't test well at the velocities I could get from my SBR.

Then again, it is your money. Spend it however you like. I don't believe the bullets are there yet, but I do believe they will be there in a couple years IF the push for the BO continues. I have spent my money. It is what it is, but I think there needs to be more development. Until then, I have other plans and projects.

You entirely missed the point and the sarcasm. You were complaining about it's external ballistics being unimpressive despite it basically matches any of the other intermediate cartridges. There's always something bigger and more powerful.

7.62x39 ammo is generally very cheap and that's usually why people buy it, because it's cheap. There's nothing wrong with that mind you. It's a decent intermediate cartridge that has modest terminal performance due to the cheap bullets that commercial loaders usually stuff into it. 7.62x39 could match 300Blackout (ballistics, not the platform considerations or subsonic), but didn't because there wasn't a market for dollar-plus rounds of ammo...the average 7.62x39 owner was more interested in finding the dirtiest Russian ammo for $0.02 a round than seeking quality. Again, no problem with it, just what floats your boat. It does explain why that cartridge never spawned much interest in high quality ammo/bullets. 300Blackout in a suppressed AR is marketed to a different crowd, one who typically has more money to burn (literally) and their willing to pay for high-tech expanding/fragmenting bullets. Nothing right or wrong about it, but it is why there is a sudden interest in quality, modest velocity bullets with excellent terminal performance (without revoking the laws of physics, these are intermediate cartridges).

From an engineering standpoint, there is no reason we couldn't have built these bullets years ago, the problem was the lack of a market. There are other intermediate 30cal cartridges, but none that natively with the AR platform (i.e. without wonky mods that kill reliability/parts interchangeability) and works subsonic/supersonic.

If you don't believe the bullets are there, start here and explain to me what else those bullets could do? Penetration is right around the 18" desired range and fragmentation/expansion isn't going to get much better without more energy/momentum, which means stepping up to a .308Win like cartridge. There's a weight/recoil penalty to do that though.
http://www.brassfetcher.com/index_files ... ACKOUT.htm

That was not how I expected it to be done, but it has potential. How's accuracy? I have concerns about the lose fit of the .17 bullet inside the other bullet. Will they load in the 300BO in the AR magazine and feed? They are also lighter than planned. Are there results on the web for the 300BO and this bullet?

All the same questions. I simply linked to the referenced bullet. Generally subsonic terminal performance is nothing to write home about; they're "quiet" and typically penetrate deep given the usual formula of shooting heavy for caliber bullets.

[smoline]

I bought a 300 Blackout upper for my existing AR. As others have said, it was a very simple matter of replacing the original .223 upper with the 300 Blackout upper. No need for new magazines or anything else. The reason I bought this was for deer hunting, as the .223 is not legal for deer hunting in VA. Ammo is a bit tough to find, but it shoots well and is accurate enough out to 300 yards or so.

[gunderwood]

Found a post about the Lehigh subsonic terminal performance out of 300BLK.
http://www.300blktalk.com/forum/viewtop ... 51&t=79280

The guys a Lehigh Defense (http://www.LehighDefense.com) have released a new bullet & ammo offering for the 300 BLK (and 300 Whisper and 300/221 Fireball). The projectile is a 200 gr Maximum Expansion projectile that is extremely effective (at fully expanding and departing full energy into targets) at subsonic velocities. They also have a 192 gr Maximum Expansion projectile. Both projectiles work out of 1:8" twist barrels.

Attached is a picture of some of the new 200 gr. Maximum Expansion projectiles recovered from gel testing after being shot in at subsonic velocities.


Below is an example of gel testing showing the full expansion beginning at about 3" in and having maximum effect up to about 9" in with total penetration up to about 17".

Looks like a 2.5-3" neck (excellent), rapid expansion, and sufficient penetration. Obviously loss some of the cavitation and fragmentation that goes with the supersonic rounds, but great performance for a subsonic.

[Molfeens]

Gentlemen,

Would it be inappropriate of me to pose a build question on this post? Don't want to hijack but I feel like it is pertinent to the 300BLK discussion.

Also, it has to do with the Silent Winter give away and I am hesitant to float out a new post for the world to see.

So...here is my question, please move or delete if this is not the appropriate place.

I won the 6.8SPC Upper with .30 Suppressor from Sterling Arsenal. When I met with them and discussed the build we touched on the fact that I already own a .223 Bushmaster 16" post ban with flash hider. SA (Sterling Arsenal) also has a number of 6.8SPC builds in front of mine which I think is a factor. Long story short, SA has offered me a 300BLK Upper in lieu of the 6.8SPC. Here are some of the "facts" as I see them which are tipping me towards going the 300BLK route versus 6.8SPC:

1. 300BLK action will cycle suppressed super and sub sonic with no gas system adjustment. 6.8SPC will but not as well and in some cases requires cutting the gas and adding a charging handle ((I THINK, FEEDBACK PLEASE)).
2. 300BLK can be SBR'd and run suppressed 100% of the time for another $200 stamp, 6.8SPC does not seem as friendly to an SBR rig. 300BLK seems to be more suppressor friendly in general. This is more cool factor than anything else.
3. If I SBR this build I can drop my post ban .223 upper on AND remove the flash suppressor/break with out going to jail. This is a big assumption on my part but if the new Lower is NFA tax stamped wouldn't I be able to do this AND suppressed the .223 upper with an adapter? (AGAIN FEEDBACK PLEASE)
4. $20 to $150 per 30 round mag depending on nonsense our government puts out could go towards build instead since my .223/5.56 mags will pull double duty with out destroying the springs.
5. I am getting into reloading, no avoiding adding a caliber but I am tending to buy the argument that the 5.56 case and .308 are probably a surer thing than the 6.8SPC in terms of being able to get brass and forge projectiles.
6. I would like to add a long range long gun to the collection but at the same time, I don't see myself getting too many 300+ yard opportunities to shoot. Assuming I am mostly at the range or on private land I will have more use for the 300BLK than the 6.8SPC. Also if I wanted to do a bolt action .308 I could for a lot less and only break it our when the 600 yard opportunities arose.

Even though the above info does not make it seem so, I am actually still open minded about the barrel.

Would appreciate any comments, fact checks or general opinion on the whole deal but especially on caliber and why, SBR or not and why and the legality of unpinning the break on my post ban and using it as well on the NFA lower (assuming I SBR).

Thanks!!

[jdonovan]

Would it be inappropriate of me to pose a build question on this post? Don't want to hijack but I feel like it is pertinent to the 300BLK discussion.

If you have to ask.... then you probably know the answer...

I know how hard it is to start a new thread.

3. If I SBR this build I can drop my post ban .223 upper on AND remove the flash suppressor/break with out going to jail. This is a big assumption on my part but if the new Lower is NFA tax stamped wouldn't I be able to do this AND suppressed the .223 upper with an adapter? (AGAIN FEEDBACK PLEASE)

Unless the upper would yield a < 16" barrel, I don't understand the problem with removing the supressor/break right now.

A SRB'd lower can use an upper of any length.

5. I am getting into reloading, no avoiding adding a caliber but I am tending to buy the argument that the 5.56 case and .308 are probably a surer thing than the 6.8SPC in terms of being able to get brass and forge projectiles.

certainly on the availabilty matrix .223, and 308 are going to beat out 6.8 every day of the week.

Would appreciate any comments, fact checks or general opinion on the whole deal but especially on caliber and why, SBR or not and why and the legality of unpinning the break on my post ban and using it as well on the NFA lower (assuming I SBR).

ah, now we get to the details. Pinned flash hider makes me assume its a 14.5 barrel with a hider to get it to legal length.

IMO the delta between 14.5 and 16 when you have a SBR isn't worth messing with. If you want a short upper, go, 10, or 12. If you want non NFA go 16.

So summing up the 6.8 vs the 300... sounds like you've already sold yourself on it, and you're looking for confirmation from us thats its a good idea.

it is. do it.

I centered my AR family on 556, 300blk, and 458 socom. The first 2 give me major spare parts interchange, brass re-use, and highly available projectiles. Also as a reloader 300blk uses magnum pistol powder in most cases, so the H110 I already stock, so it fits nicely in the reloading plan.

Subsonic 300 blk is VERY fun. Even my tinfoil wearing friend had enough fun he's contemplating getting on one of 'dem gov't lists so he can get a supressor.

458 uses the same mags, tho GI mags work much better than pmags. And if a 458 wont stop it, I need to re-evaluate why I''m messing with it in the first place.

If you're in NoVA and want to try a 300, we might be able to arrange a test-drive at a local range.

[breacher]

Man...everybody is buying one of these! Maybe I should have ordered one instead of a AR57...oh well, I'll be the odd man out. J1mmyd just got one too, I'll shoot his.

Molfeens get the 300 BLK with 9" barrel, Suppressor... that is a sweet kit right there! If your gonna run a can, don't do 16" or 18" barrels, you will hate life.

[gunderwood]

I'd go 300BLK over 6.8SPC every day of the week. If I wanted a longer range AR15, I'd build a 6.5Grendel. If you decide to SBR it, I'd go with a 8-12.5" barrel in 300BLK. A 9" 300BLK is approx. equal to a 14.5" 5.56mm as far as muzzle energy, but suppresses much better (sub or super) and a 7.62mm expanding bullet like the Barnes is going to beat a fragmenting 5.56mm IMHO.

Just realize you can't leave the state with the SBR without ATF permission ahead of time. Understand what registering actually means. Also, NFA items aren't legal in all states.

As for your post ban, it sounds like the issue is that the barrel is actually 14.5" and with a pinned flash hider and suppressor they offered. Thus, while they offered you a 300BLK barrel, the thread-on suppressor is actually still 6.8 (which will work fine on a 5.56mm), but in order to use it on your upper you need to remove the pinned hider? At that point you have an SBR in 5.56mm. I'm not sure how the thread-on suppressor is going to work on threads that have a hole drilled through them. I guess, it might work if someone cleaned up the threads for you.

A 16" barrelled 300BLK is a very good hunting option. The ME is about equal to a 24" barrel 5.56mm, but obviously much better bullets.