.300BLK - Poised to win or doomed to fail?

68wj said:

It is spin to claim that (unless you are selling it to the .gov/.mil) using 5.56 mags and bolts is a benefit.

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That is some pretty big rationalization that parts commonality with the #1 cartridge is not a benefit.

My plan is to use 300 BLK for most ranges (99.9% of my shooting is within 200 yards), and a 308 for when I want more range - and skip everything else.

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Yeah that's what I plan to use it for too.

125 gr. Ballistic Tip at 2,200 fps is pretty awesome hunting round inside 300 yards.

220 gr. OTM subsonic with a suppressor is pretty awesome too.

There are a lot of bullets to choose from.

It's a fun cartridge. Nevermind the effectiveness of it. It's just fun.

I had the opportunity to shoot subsonics out of SBR and it's plain just fun. Those 220 gr. bullets hit pretty hard too. There's a lot of momentum behind that fat heavy bullet

Checkout these hickok45 videos:

http://www.youtube.com/watch?v=Sd_2tcj7P4s
http://www.youtube.com/watch?v=Q5ALp8-d3dQ
http://www.youtube.com/watch?v=GkTb875bdtw

He looks like he's having as much fun as I was.

Ragsdale 30 cal said:

Where the 6.8mm SPC design is screwed up is it's focused too much on long range terminal performance. You don't need long range terminal performance in an intermediate cartridge.

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Source? I think you meant the Grendel. The 6.8SPC was designed specifically to exceed the performance of the 5.56 from a short barreled AR-15 out to 300yds. The long range (beyond 300yds) performance of the 6.8 is not very good. .270 bullets that will fit in an AR-15 magazine in the 6.8 cartridge have poor BCs and don't carry energy downrange very well at all and they get pushed around by the wind to an extreme. The .277cal was chosen as a good balance of bullet weight and length to be able to be pushed fast enough, have enough sectional density to penetrate once it hits something, and fit in the magazine. It is a true intermediate cartridge that really shines at closer ranges.

The .300BLK has its benefits but I would have preferred it in a 7mm package. I still don't understand the fascination with a .30cal bullet.

The .300BLK has its benefits but I would have preferred it in a 7mm package. I still don't understand the fascination with a .30cal bullet.

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One could argue that, but it would have been much less successful. The KAC PDW round is a 6mm, but otherwise the same.

Hmmm.. So we have a combat rifle shooting a .30 caliber bullet with design limitations (small case/powder capacity) that give it a realistic effective range of a couple hundred yards. If this is ground-breaking then it sounds like we are 60 years or so behind Kalashnikov lol. In today's market though, its a pretty good business decision. Make anything you can slap on or into an AR design and you have something that people will buy.

The concept is from the Stg.44 - 70 years old.

125 grain at 2250 fps. Ceptin' now it works in an AR with 30 rounds in a normal magazine.

http://en.wikipedia.org/wiki/StG_44

Well not to hijack the thread but I just took the plunge and bought the parts for a 7.62x40WT and can't wait to put it together...blackout and 6.8 were runner ups but the gun is not going to be suppressed and I have the brass I need to make the 7.62x40 brass and the bullets....not too hard to see the advantage for me.

It is spin to claim that (unless you are selling it to the .gov/.mil) that using 5.56 mags and bolts is a benefit. It can also be considered a limiting factor.

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With 5.56 or 300BLK I can get premium quality bolts from several different companies and hey, guess what, I already own several of them (that I got for good prices). I also get the strongest common bolt design because the head hasn't been hollowed out to make room for a larger cartridge case head. With 6.8 SPC I can use a DD or LMT bolt if I'm lucky enough to find one, and otherwise I'm getting something unknown like a DPMS. And I'm paying extra for it.

With 5.56 or 300BLK I can use premium quality mags (D&H milspec, Magpul, Troy, others) that cost only $9-14 a piece and, guess what, I already own a bunch. With 6.8 or 6.5 I can use iffy quality mags for about $20 each if I can find them (CP? ASC? What tomorrow?) or I can use slightly less iffy mags for $40 each if I want to spend that much. The D&H 6.8 mags were promising but initial reviews aren't good. Maybe this will change. Maybe it won't. I've been waiting 7 years to see 6.8 SPC products come down in price and increase in availability. Sure, they can be found reasonably well, but I can't buy them at each and every one of 5-10 different companies I order from. Any given item might be at two of those companies.

And then there's ammo. There is a real chicken and egg problem for 6.8 SPC, but there have been 8 years for it to get straightened out. I can't find ANY 6.8 SPC ammo for less than about 80 cents/rd, and rarely at that. Reliable sources of 6.8 SPC charge about $1-1.20/rd. 6.5 Grendel is more mixed - you can get Wolf Gold (variable reports of quality) for only $65-75 cents/rd, but for high quality stuff you're over $1/rd again. Any enterprising ammo maker could fix this, but in 8 years none have.

In stock as of now. It won't last:

http://www.midwayusa.com/product/54...62x35mm-115-grain-full-metal-jacket-box-of-20

Just because 300 BLK works well with suppressors does not mean that it needs one. Just because it is efficient from short barrels does not mean that it does not benefit from longer barrels.

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Yes, I understand this, thanks

I was merely addressing two of the cited benefits of the 300 BLK that set it apart from other pre-existing, AR rounds: subsonic capability for suppressors, and efficiency out of short barreled rifles. Neither of which are a big deal for the 90% of AR owners who won't be buying SBR uppers or Suppressors for their rifles. Even with a longer 16 inch barrel, the velocity numbers I can find are in the 2200 fps range... somewhere between the .30 carbine and the 7.62x39... not exactly glowing numbers for a cartridge billed as a viable hunting round. I'm sure it will work, but it seems to me there are better options in the 0-300 yd range. Also, I've never heard the 6.8 billed as a cartridge predominately meant for ranges of greater than 300 yds... I believe it is a 300 and under round meant for increased effectiveness over the 5.56.

That is some pretty big rationalization that parts commonality with the #1 cartridge is not a benefit.

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A benefit, sure, a major benefit? Seems like a stretch to me, None of my other rifles have parts commonality, and I haven't felt the sting of that logistical burden yet.

I don't really tout the suppressor thing. I see the benefit as a 30 caliber round for AR15s that works with 30 rounds in normal magazines.

The 300 BLK has 16.7% more energy than even the hot Lapua 7.62x39mm ammo at 300 meters (that ammo is over $60 a box). It is *way* more than 30 Carbine - in fact it has as much energy at 190 yards as 30 Carbine at the muzzle.

300 BLK from a 6 inch barrel matches the 30 Carbine from an 18 inch barrel.

If I am launching a 125gr 7.62x39 at 2350-2400, and also the same 125 gr bullet .300 blk at 2200, the 300 BLK will not have more energy at any range.... lets compare apples and apples here.

If I am launching a 125gr 7.62x39 at 2350-2400, and also the same 125 gr bullet .300 blk at 2200, the 300 BLK will not have more energy at any range.... lets compare apples and apples here.

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I don't consider hand loads credible. Sorry. Factory ammo only. 300 BLK has 16.7% more energy at 300 meters than the best AK ammo made.

The data GTscotty provided is accurate and also applies to many factory loads.
Here is an example. 16" barrel. Let me know if you need any other factory ammo on any caliber.
I have many different type of uppers tested.....

Gtscotty said:

the 300 BLK will not have more energy at any range

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How come the AVE light is not on? What is the average velocity with a 10 shot string?

2369 fps, 0.280 BC - 629 ft-lbs at 300 meters.

300 BLK - 2215 fps, 0.338 BC - 640 ft-lbs at 300 meters.

So it takes almost 300 meters before the 300 BLK outperforms that ammo (it passed the Lapua ammo at about 120 yards).

http://www.midwayusa.com/product/14...out-308-diameter-125-grain-open-tip-match-otm

Don't question everything you do not like.
I am not arguing with anyone. I love the blackout. I just provided some facts here. Per my data average for that load is 2.369. 16.1" inches barrel precisely.
Why don't I have the average picture? Because I am testing a few strings after I am done with the hard work (actual reloads) and just use a 3 or 4 shots of the same factory box, several brands in the same string, just for curiosity to have some baseline data. This is not by any means a comprehensive testing of factory ammunition. Specially Russian puffins.
We love all AR-15 wildcats not because the are the greatest but because we love the AR. If it they were the greatest you will see them as a popular option in the bolt department.
The Blackout is here to stay. The 300 whisper has been a great variant and now with the SAAMI spec and plentiful brass is even easier than ever before.

By what data are you using that demonstrates better penetration or expansion?

I would be surprised to see a ballistic gelatin test with a 6.8mm SPC bullet penetrating or expanding more than .300 Blackout bullet of equal weight and construction. The two aren't that far apart ballistically.

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Sorry, missed this when I was reading the thread earlier.

First, I never said that the 6.8 would have better expansion, just that given similar bullet weights and similar bullet construction it would likely penetrate better. I'm referring of course to the differences in sectional density between similar bullets weights in the .277and .30 cal. Other things equal, bullets with higher sectional density tend to penetrate more than those with lower sectional density. Of course this relationship can be modified by the use of fancy solid copper or bonded bullets, but then again such rounds get expensive quick. There is something to be said for being able to get sufficient hunting penetration out of standard bullet styles with a given cartridge.

I hope everyone has a good new years!

300 BLK tends to penetrate well as there are so many 308 bullets which do so when at 300 BLK velocities.

http://www.300aacblackout.com/resources/300AACBlackout06OCT2010.pdf

6,8 penetration here:

http://www.weaponevolution.com/forum/showthread.php?1598-Remington-6.8-SPC-Guide.

The largest diameters of the recovered bullets were 0.53 and 0.55. 300 BLK expands to a larger diameter even from a 9 inch barrel - even from 100 yards, and still penetrates more.

rsilvers said:

6,8 penetration here:

http://www.weaponevolution.com/forum/showthread.php?1598-Remington-6.8-SPC-Guide.

The largest diameters of the recovered bullets were 0.53 and 0.55. 300 BLK expands to a larger diameter even from a 9 inch barrel - even from 100 yards, and still penetrates more.

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Is that claim in relation to your TSX gel post above? I only saw 1 6.8 110 TSX gel shot on the link provided and it did not show recovered diameter and has a penetration of 22". I would however expect the .300 TTSX to have optimal expansion due to its cartridge application design.

LE - they never shoot even at 100 yards - and typically 30 yards or less. They need the affordable practice ammo - which for 300 BLK can be less than 40 cents a round for govt users.

And the needs of home defense are the same.

I don't think anyone was saying that the 300 BLK, using Barnes TSX bullets wouldn't out penetrate a 6.8 using lighter weight TSX, or standard construction bullets, mostly because that's not a fair comparison.

rsilvers,
I wish your company was pushing the 6.8 SPC or the 6.5 Grendel, if your and (AAC's) marketing persistence and tenacity were directed towards those two calibers, I'm sure consumers would have more and better options in each.

p.s.~ What are the trajectory numbers for the 300 BLK and a 6.8 SPC (spec II) with similar weight and bullet type out of 16 inch barrels? Not trying to put the calculations on someone else, but I'm currently in an airport and it seems like every other sight I try to visit is blocked...

With a 200 yard zero and a 16 inch barrel, 300 BLK UMC ammo is +- 3.5 inches out to 237 yards.

The SSA Tactical 6.8 load - 85 TSX, at 2920 fps, is +- 3.5 inches out to 286 yards.

That is the reality of the difference - 49 more yards. Yes, that is significant for people who want to optimize for longer range.

I hate the comparison threads we see all the time. Specially those that are completely unjustified, unfair to any rounds or wildcat and with inaccurate data included to discredit any of them.
Those rounds are appealing to different people for different reasons and occasions and purposes.
The blackout is a great round for what many folks need at average ranges and gives you the option of great subsonic work. Same thing for Kurt's 7.62x40.
For supersonic work a modern 6.8SPCII 16" barrel with the latest cases and 1.0 freebore will send a 85gr Barnes TSX at 2900fps. Also it will send a 110 gr TSX BT with SD .205 and G1.323 at 2690fps. In subsonic mode there is no match for the blackout with bullets like the 220gr-240gr SMK available.
Any TSX in any caliber is devastating even the 223rem in 62gr or 70gr. It has more to do with bullet construction and terminal ballistics properties than anything else.

So comparisons like I read earlier on "The blackout shoots like a 30-30" or "it is similar to the 6.8" type of claims are ridiculous. The people go and believe that w/o even bother to look it up. The 30-30 is a great cartridge mainly dedicated to lever and single shot rifles so it is not fair to invite this one to this party. Commercial 30-30 loads pushes a 160gr bullet above 2400fps and it has the capacity to take advantage of a longer barrel. The data is available everywhere. The 7.62x39 russian can also do a great job with heavier rounds, also commercially available.

But there is something that has not even been discussed in this thread that favors the blackout and the 7.62x40, and any 223 rem offspring, above any other and nobody has mentioned this (I think). If you single feed one of this rounds one can further increase performance by extending COAL but the problem is just that, single feeding. But the good news is that the standard AR bolt face in any of their offspring offers a simple solution to increase this in a SPR configuration using VLD mags. We loose round count but we further enhance tactical advantage based on the small footprint of standard bolt configuration. Any other larger bolt face is automatically excluded from this possibility and although I see marginal use some hunters, special operations folks and simply enthusiasts, might find it useful.

As I said, the blackout is staying as a great alternative. It is simple, reliable and it fills many purposes. Not everyone's purposes and that is ok. One can never have too many upper variants anyway!

1stmarine said:

as i said, the blackout is staying as a great alternative. It is simple, reliable and it fills many purposes. Not everyone's purposes and that is ok. One can never have too many upper variants anyway!

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