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Old October 27, 2012, 10:28 PM   #1
Bwbraven
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Thought on 6.8 spc in Ar-15 platform

Is the 6.8 spc here to stay or will it fall to the way side with the 300 black out taking alot of interest lately. What's your thoughts? Would you buy a Ar or any rifle chambered in 6.8?
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Old October 28, 2012, 02:20 AM   #2
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IMO the 300 blackout is a crap round . At 120 grains it has good velocity at 2,100fps but terrible BC . At 220 grains it has good BC but terrible velocity 1,050fps . A 1911 can have that kind of ballistics with a 200+ gr bullet . I don't know the exact numbers but I would think the lighter blackout will stop traveling SS at about 500 yards or so and the 220gr bullet never getting there . Making 500yds it's max effective distance .

Thats just my thoughts on the blackout . Im sure there are some good uses for it . Maybe if you want a hard hitting CQC weapon the 300 blackout would work well . I could see it working well in urben areas where most of your shots are 100yds or less . The longest shot may be 2 to 300 yards tops .

The 6.8 has much better ballistics . It's bassically a 270 in a smaller case .It has a velocity of 2,400+fps and a range of 900yds or so .

I do plan to build a 6.8 AR but Im am torn between building the 6.8 or 223 wylde 20" bull barrel for my next build .

EDIT . My point is the 6.8 has much more potential and uses therefore I feel it will be around awhile .
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Old October 28, 2012, 02:32 AM   #3
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I thought I read recently that Hornady plans to ramp up production on ammo for it.
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Old October 28, 2012, 08:06 AM   #4
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Check out the 68 forum and you'll get the feeling that it has quite the support from the industry. DD, Wilson Combat, PSA, Stag Arms and more companies make barels or complete rifles. SSA, Hornady, SB, and Remington make ammo and you can reload. Also hearing the rumor that Federal will get in the mix with ammo and Wolf maybe next year.
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Old October 28, 2012, 10:36 AM   #5
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I had the same question..... I bought a 6.8 ar


Couldnt be happier

More vendors are coming on line.

6.8 Bullet performance is
Better at all ranges than the 300 blk.

As long as there are 270 rounds to reload, (up to 130 grain) there will be bullets for the 6.8.

6.8 has 80% of the 308 and is a great caliber for deer and hogs

I think you will be very happy with the 6.8
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Old October 28, 2012, 11:48 AM   #6
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I read in guns and ammo that more companies were doing the 6.5 Grendel but haven't seen anything along those lines of the 6.8.
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Old October 28, 2012, 12:16 PM   #7
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Quote:
Originally Posted by Bwbraven
I read in guns and ammo that more companies were doing the 6.5 Grendel
That's true since they became a SAAMI cartridge, but they still have a long way to catch up. One look at loaded ammunition at Midwayusa will give you an idea how far: they list (6) 6.5 Grendel loads, (30) 6.8SPC loads, and (18) 300 BO loads.

Quote:
Originally Posted by Marquezj16
Also hearing the rumor that Federal will get in the mix with ammo]
Not a photoshop:

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Old October 28, 2012, 12:37 PM   #8
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If you plan on shooting distances greater than 150 yards, want a semi-auto to do it but don't want the projectile to be a 22 caliber bullet, 6.8 spc is a good choice. If any one of those three things don't apply than you would be better served by something else.

Quote:
IMO the 300 blackout is a crap round .
When the bashing of other cartridges starts early you know it's a thread about the 6.8 spc. The inferiority complex that some 6.8 shooters have hurts my head...
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Old October 28, 2012, 12:55 PM   #9
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300BO is crap? No.
Live up to the hype? Also no.

I had a 300 Whisper for a short time before I sold it and went 6.8. 300BO/300Whisper/300-221Fireball is good for a subsonic SBR with a suppressor, but it just doesn't have the velocity or BC to keep up with the either 6.8 or the 6.5.
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Old October 28, 2012, 01:00 PM   #10
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The latest Shooting Times has a long article on the 6.5 Grendel which shows that the ballistics are superior to both the 5.56 and the 300 in the M4 platform, and slightly better than the 6.8. You might want to take a look before making a decision.
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Old October 28, 2012, 01:02 PM   #11
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I have no regrets buying mine. I do wonder what's happened to the 90gr varmint loads of late- it's getting more rare that you can find any loads below 110gr. However, sonce I got into it- loads of 110gr and up have quadr... gone way the heck up.
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Old October 28, 2012, 01:16 PM   #12
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Quote:
Originally Posted by spacecoast
The latest Shooting Times has a long article on the 6.5 Grendel which shows that the ballistics are superior to both the 5.56 and the 300 in the M4 platform, and slightly better than the worst 6.8 load available. You might want to take a look before making a decision.
FTFY. 6.5 Hunting bullets also don't have the high BC of the match bullets.
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Old October 28, 2012, 05:15 PM   #13
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I also dont care for the 300 blackout round. Its almost as pathetic as a 7.62x39 and nowhere near as good a caliber as the 7.62x51/.308. If I was looking for a hunting caliber for my AR it would either be a 6.5 grendel or 6.8spc. I think the 6.8 is all around better than the 5.56.
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Old October 28, 2012, 08:21 PM   #14
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I like the 300 BLK for what it is a harder hitting mid range(300 yds or less) caliber for the AR-15 platform that only requires a barrel change to convert. I don't believe anyone is saying you could win 1000yd matches with it....
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Old October 28, 2012, 11:04 PM   #15
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300BO is crap? No.
Live up to the hype? Also no.
What hype? It does exactly what it was advertised to do. If you are talking about people being enthusiastic about the caliber, that's the pot calling the kettle black. All these calibers are wimpy compared to ones that fit into a $300 short action bolt gun. That's just the nature of the game if you want to shoot it out of an AR15. A 300blk shoots a bigger caliber bullet and fits more rounds into a magazine so it's not a crime for it to have a lower muzzle velocity.
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Old October 28, 2012, 11:38 PM   #16
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6.8 is likely here to stay.

It is also likely to remain like the 10mm or 41 Magnum is to handgunners, kind of a niche loading, for people who like to hunt medium game in states where the minimum caliber is above 22.

The 6.5 Grendel is an interesting cartridge choice, but terminal ballistics aren't enough of a difference to separate it from heavy 223 loads, or 6.8 loads, and cost isn't low enough to tempt too many. It isn't exactly a true long range round (you run in to the same "run out of steam" issues as you do with anything put through the AR magwell,, just a tad further, but then you get into making your light handy rifle a big heavy monstrosity...)

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Old October 30, 2012, 10:26 AM   #17
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At 220 grains it has good BC but terrible velocity 1,050fps . A 1911 can have that kind of ballistics with a 200+ gr bullet
Not even close. The BC of the subsonic 300 BO round is far better than a handgun round, and therefore it shoots much, much flatter.

The 300 BO is a terrific round for its intended purpose: to allow a 5.56 AR to be easily switched to a .30 caliber bullet that can also work well with subsonic loads for suppressor use. The supersonic loads will duplicate the 7.62x39, and the subsonic loads allow you to be much quieter while supressed and yet still cycle the action. And the 300 BO subsonic rounds shoot much flatter than any subsonic handgun round.
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Old October 30, 2012, 11:19 AM   #18
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The 6.8 has much better ballistics . It's bassically a 270 in a smaller case .It has a velocity of 2,400+fps and a range of 900yds or so .
If by that you mean "A 270 in a smaller case with 2/3 the muzzle velocity of the .270 WIN, and restricted to short, stumpy inefficient bullets, just in a smaller case" .... then, yeah, then "bassically" that's true ...... and "bassically", "a .30/30 is a .30-06 with 2/3 the velocity and restricted to inefficient round nosed or flat point bullets, just in a smaller case".....

900 yards?

A 110 gr .277 V-Max, assuming you could launch it @ 2400, would be subsonic past 600 ........ and would drop 46 FEET from a 100 yard zero by 900 yards ..... Wind drift would be measured in double digits as well .... energy would be down to .380 ACP levels ..... I you were trying to break windows in an apartment building, it'd do that pretty well ...... but so would .223.....

I like the 6.8, as a way to add lethality to the M-4 platform ..... but it is what it is, and it is not a "pocket .270". I think it'd be a great short range round for whitetail, if 130 gr bullets could be seated out long enough to launch at 2500 or so ..... but the 6.5G can do all that....

The 300 BLK is designed for suppressed SBR use.... I'd be all over that if that's what I needed done .....
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Old October 30, 2012, 01:33 PM   #19
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Not even close. The BC of the subsonic 300 BO round is far better than a handgun round, and therefore it shoots much, much flatter.
Yea I new I was going to catch some grief on that one .

Quote:
If by that you mean "A 270 in a smaller case with 2/3 the muzzle velocity of the .270 WIN, and restricted to short, stumpy inefficient bullets, just in a smaller case"
Short answer yes all I meant by this is they shoot the same projectile

Quote:
A 110 gr .277 V-Max, assuming you could launch it @ 2400, would be subsonic past 600 ........ and would drop 46 FEET from a 100 yard zero by 900 yards ..... Wind drift would be measured in double digits as well .... energy would be down to .380 ACP levels
I do not have the data on the 110gr v-max but that sounds about right do to it being a shorter lighter bullet with a BC of .370 .

However I was using the data on the 130gr sst with a BC of .460 . This bullet will shoot 900-ish yards . and yes both of these bullets have significant wind drift and bullet drop . Cus I don't have all the data on the 110gr v-max . I would guess the 130gr sst does a little better in both these areas .
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Old October 30, 2012, 01:50 PM   #20
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Quote:
Originally Posted by jimbob86
A 110 gr .277 V-Max, assuming you could launch it @ 2400
You can launch a 110gr .277 Vmax at 2400fps, all you need is a 10" barrel. From a 16" barrel, it's much closer to 2700 fps.
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Old October 30, 2012, 03:15 PM   #21
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I think it'd be a great short range round for whitetail, if 130 gr bullets could be seated out long enough to launch at 2500 or so ..
I've been reloading 6.8 for a couple of years now and I've never loaded a bullet heavier than 120 grains. There's just no need for that much bullet weight in that case. For deer or other big game, you just need to pick either a bonded bullet or a Barnes X bullet.

I like my 6.8 a lot. I have a wide variety of AR's but the 6.8 would be my choice if hunting was my main interest. A Barnes 85 or 95 grain bullet driven to max velocity in an SPC II chamber does amazing things to pigs and deer. I shoot a lot of 5.56mm and I've also reloaded it with the heavier bullets and used it for hunting deer from a stand. But the 6.8 takes your 5.56mm sized AR and bumps it up one level when it comes to the capability of the round. No one will argue that it is a 7.62 NATO round but the rifle is a lot smaller/lighter than an AR-10 as well.

Everybody should have an AR in 5.56mm. And then they should also have one in .22 LR. But for AR #3..... go 6.8!

Gregg
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Old October 30, 2012, 10:05 PM   #22
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You can launch a 110gr .277 Vmax at 2400fps, all you need is a 10" barrel. From a 16" barrel, it's much closer to 2700 fps.
A 110 gr V-Max 6.8 SPC to 2700, from a carbine length gun? Really?

I'd like to see some hard data on that..... everything I have seen is maxing out around 24-2500 ....

And 130 gr loads are generally too long to fit in an AR magazine .... and take up too much case capacity, leaving too little room for propellant.... so velocity suffers.

How fast are you thinking you are launching a 130 SST there, Mg? Even if you launched it at full house 270 WIN velocity (3100!), it'd still drop 17 feet from a 100 yard zero, and have nearly 6 feet of wind drift in a 10mph crosswind..... but you'll never get that much velocity out of the 6.8, in any barrel length ...... it's not effective at 900 .....


To stay supersonic at that distance, you need more efficient bullets than are generally available in the .277 bore ..... Berger makes a .277 VLD with a .531 G1 BC ..... but that weighs 150 gr .... good luck gettting even 30/30 belocity out of that in the 6.8 ......
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Old October 30, 2012, 11:43 PM   #23
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Check these out . Looks like getting the velocity up with the 6.8 is no problem . My guess is none of these loads are maxed out do to liability concerns .

http://www.targetsportsusa.com/p-334...mmunition.aspx

And this one , holy cow http://www.targetsportsusa.com/p-117...box-of-20.aspx

http://www.hornady.com/store/6.8mm-SPC-110-gr-V-MAX/

http://www.hornady.com/store/6.8mm-SPC-120-GR-SST/

I'm in no way saying that the 6.8 is a great 1,000 yard round . Just that it has more versatility and potential then the 300 blackout in the ways I would most likely use them . I was making the point to the OP . IMO the 6.8 is more virsatile then the 300 .So I believe it will be around and used more by the general public .
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Old October 31, 2012, 06:45 AM   #24
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Quote:
Originally Posted by jimbob86
A 110 gr V-Max 6.8 SPC to 2700, from a carbine length gun? Really?
http://shopwilsoncombat.com/68-SPC/products/409/

There also seems to be a myth that longer barrels are useless in the 6.8, here's what it's capable of with a 24" barrel.
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Old October 31, 2012, 06:54 AM   #25
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I have begun to find once fired 6.8 brass, discarded at the range. I think that it is here to stay. Just bought an 18" Stag upper to add to my 16" carbine.
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