6.8 SPC vs 5.56

[SLG]

I have had the same 6.8 accuracy experience as SLG, as I recall using the same high end brand upper, and many of the same loads.

If it is for hunting, why not the 6.5 Grendel on a Brockman CZ, which is handy, reliable, durable and accurate?

I love the little CZ, and all turnbolts in general, but I'm focused on the better ergonomics of the AR, so that's what I'm using. Plus, there is only a small weight penalty with the AR over the CZ, and I do get a gun I'm most familiar with.

But, I just zero'd a newish GAP 308, and it is pretty sweet. Hard to stay faithful to one long gun for me.

[oldtexan]

There is so much gold here. I am a big fan of the 6.8 SPC. I don't hunt four legged animals, just twos. The 6.8 SPC is a near perfect law enforcement round if you take all the emotion out of the equation and just look at it logically. Optimized for good patrol rifle sized guns. Good on cars. Can be put in sniper systems optimized for typical LE sniper engagement ranges and scenarios. Low recoil and as easy to run as a 5.56 gun. You get 80% of a .308 without many of the issues in recoil, penetration, and size of the .308 systems. The list goes on. What has always been TOTALLY baffling to me is the relentless effort to push it as a hunting cartridge. As a person who hunts evil humans, I have never understood wanting to hunt Moose with a AR-15 based platform. I have a bunch of really awesome hunting rifles that are far more practical for this endeavor if I ever decided that I needed to start killing four legged animals. Essentially, the 6.8 SPC is a under appreciated LE system, that I blame a lot on a whole bunch of folks trying to make it into a hunting round.

I also do not want to be one of those guys who craps on someone else's world without a good reason (no, really....). I understand that some folks want to hunt with the AR. Okay, got it. So I look at all sorts of stuff, and boy it sure looks like 6.5 Grendel makes a better hunting round than the 6.8 SPC does. So I figure if I really wanted a sporting AR, the Grendel makes a ton of sense.

I am working on the "New 30-30 Concept" for awhile. I have been lazy on the paperwork, but when it is done, my Texas 30-30 12.5 LMT LM8 in 6.8SPC is capable of taking all the game in Texas (which is smaller than up north), should slay pigs like a boss, and is very acceptable in this state for people as a defensive carbine, and would make a great LE carbine. A 6.5 version may make more sense farther North, or for someone who is far more concerned about the hunting aspect as I am.

Nyeti, what has been your experience with the 6.8 in an AR in terms of accuracy? What kind of groups are you getting with what loads and how does this compare to your experience with accuracy of 5.56mm in an AR?

[Dagga Boy]

In sniper school I was able to hit a penny at a 100 yards. Weirdly, that gun shot better with a shortened barrel that started as an 18 and was cut to 16" by Barry Dueck and set up to take a Surefire can. It also shot well suppressed. It was not even close to the bolt guns, but it was certainly a solid 1 MOA gun. My others are similarly accurate to my 5.56 stuff in similar configurations. Where I saw a good difference was in the shoot off at the school, I was at 300 yards shooting USMC Scout-Sniper who was a full time sniper at a large, busy agency now. He was running a custom 700 in .308 and mine was a 16" LMT MRP with the 16" SS match barrel. We were shooting in terrible wind conditions with a full value window coming out of one canyon and a hard gusting wind out of another direction near the targets. This is where I found the 6.8 to be better than the 5.56 in particular. We shot near identical groups in nearly the same place on the targets, but the other guy got a bit of a tear into a scoring ring better. The difference was literally the difference between a .270 and .308 hole. Keep in mind we left 25 other guys behind us to get there. Now when we were shooting 100 yard groups, polar opposite situation. My point is that the guns may not group as well under ideal shooting conditions for trying to make little holes, but they seem to be easy to shoot consistently under field conditions. Hopefully, that makes sense.

Another issue is that the 18" barrel would consistently shoot a single round out of the group on the first round loaded from the magazine. It was not nearly as pronounced with the cut 16" barrel. That is another factor as well in which some factors will be in play that are individualized with each barrel.

[DocGKR]

So do you think there is anything in your description of a 6.8 that my 6.5 can't do? Aside from the fact that I wouldn't carry it on duty (if I could). Other than the Long Range aspect of the 6.5, I see the 6.8 and the 6.5 as filling the same power roles vis-a-vis the 308.

With minor variations, all of the 6.x cartridges for the AR15 FOW essentially are in the same category (as is .300 BLK), due to the limited case capacity. Ignoring durability and reliability, there are currently more barrier blind loads available in 6.8 mm. 6.8 mm also tends to work better in shorter 8-12" barrels. Both 6.5G and 6.8 mm are fine with 16" barrels for the majority of LE duty and civilian hunting needs, with an accuracy edge to 6.5G at longer ranges.

For a duty weapon, a durable, reliable, proven 16" .308 semi-auto is likely a better choice than a 6.5G for many reasons, especially since the 1/8 twist .308 16" AR's are proving accurate out to 1000 and a bit beyond.

In a typical service carbine with a 16" or shorter barrel, using mass produce duty ammo, 6.8 mm offers essentially the same accuracy and trajectory as 5.56 mm out to typical carbine engagement distances (usually limited by terrain and common carbine optics--RDS, ACOG, low power variable in the 1-6x range) as demonstrated in the USG accuracy data posted on page 5 of this thread.

For a non-paper punching long range rifle in 6.5/.260, something with more case capacity than 6.5G is preferable--at least 6.5 Creedmore/.260 Rem.

For a new idealized GP military rifle/SAW caliber, almost all research indicates that a cartridge in the 6.5-7mm range with a case capacity of at least 40 gr propellant and a case head intermediate in size between those typically used in AR15's and AR10's is the preferred choice--thus the existence of AMU's .264/.277 USA.

[Jeep]

The 6.8, 6.5 and .300 Blackout are all interesting calibers, but for defensive purposes my view is that us non-LEO civilians are probably generally better off with a 5.56, a semi-auto or pump shotgun and a 9 mm pistol.

Among other things, standardized ammo, and the weapons for which it is standardized, tend, as mentioned above, to be more reliable and they also tend to be cheaper--which allows for much more training.

If I were back in the military, I'd be pestering the powers that be to consider transitioning to a caliber like the 6.8 (thought they won't--we are going to be using the 5.56 for a long time) and from nyeti's and Doc's comments it sounds like it has a lot of promise as an LEO round. The 6.5 obviously has a lot going for it as a hunting and possibly designated marksman round (though that won't happen either).

But for civilian self-defense, I think the standardized calibers are the way to go and I think at most civilian SD ranges the shotgun is probably the long gun of choice.

[Symmetry]

for defensive purposes my view is that us non-LEO civilians are probably generally better off with a 5.56, a semi-auto or pump shotgun and a 9 mm pistol.

It is what I use as a LEO too, and it is very difficult to find justification to go outside that box.

[witchking777]

With minor variations, all of the 6.x cartridges for the AR15 FOW essentially are in the same category (as is .300 BLK), due to the limited case capacity. Ignoring durability and reliability, there are currently more barrier blind loads available in 6.8 mm. 6.8 mm also tends to work better in shorter 8-12" barrels. Both 6.5G and 6.8 mm are fine with 16" barrels for the majority of LE duty and civilian hunting needs, with an accuracy edge to 6.5G at longer ranges.

For a duty weapon, a durable, reliable, proven 16" .308 semi-auto is likely a better choice than a 6.5G for many reasons, especially since the 1/8 twist .308 16" AR's are proving accurate out to 1000 and a bit beyond.

In a typical service carbine with a 16" or shorter barrel, using mass produce duty ammo, 6.8 mm offers essentially the same accuracy and trajectory as 5.56 mm out to typical carbine engagement distances (usually limited by terrain and common carbine optics--RDS, ACOG, low power variable in the 1-6x range) as demonstrated in the USG accuracy data posted on page 5 of this thread.

For a non-paper punching long range rifle in 6.5/.260, something with more case capacity than 6.5G is preferable--at least 6.5 Creedmore/.260 Rem.

For a new idealized GP military rifle/SAW caliber, almost all research indicates that a cartridge in the 6.5-7mm range with a case capacity of at least 40 gr propellant and a case head intermediate in size between those typically used in AR15's and AR10's is the preferred choice--thus the existence of AMU's .264/.277 USA.

So now I'm gonna throw everyone for a loop,what about a reliable g2 recon in .308 with a muzzlebrake in a 16" barrel? More food for thought,curious to see everyone's input

[Dagga Boy]

So now I'm gonna throw everyone for a loop,what about a reliable g2 recon in .308 with a muzzlebrake in a 16" barrel? More food for thought,curious to see everyone's input

The gun, or ammunition wise. If its the gun.........DPMS.....have not had good luck with their 5.56's, so I am twice as leery of a .308 version. Easy suggestion that fixed me as to dreams of running a .308 like a carbine.....go take a difficult 3-5 day class with one and let me know if you think it is viable. I took a LaRue Texas Ranger rifle through a 3 day EAG Advanced Low Light Carbine class that cured me pretty quick. The reality is that the LaRue gun would have been better than my 6.8 SPC LMT MRP in sniper school (the LaRue shoots .49) and the LMT would have been a great choice for the EAG Low light school.

We all "get" 5.56 logistically for L/E, but if you look at the round alone strictly on its performance and attributes, in my mind, it is the ideal LE caliber. It will likely only get adopted on the internet as predicted by Vickers, but the LE realm is one place where it could have been a really viable alternative and would have made logistical sense as far as a single rifle caliber for all missions.

[witchking777]

The gun, or ammunition wise. If its the gun.........DPMS.....have not had good luck with their 5.56's, so I am twice as leery of a .308 version. Easy suggestion that fixed me as to dreams of running a .308 like a carbine.....go take a difficult 3-5 day class with one and let me know if you think it is viable. I took a LaRue Texas Ranger rifle through a 3 day EAG Advanced Low Light Carbine class that cured me pretty quick. The reality is that the LaRue gun would have been better than my 6.8 SPC LMT MRP in sniper school (the LaRue shoots .49) and the LMT would have been a great choice for the EAG Low light school.

We all "get" 5.56 logistically for L/E, but if you look at the round alone strictly on its performance and attributes, in my mind, it is the ideal LE caliber. It will likely only get adopted on the internet as predicted by Vickers, but the LE realm is one place where it could have been a really viable alternative and would have made logistical sense as far as a single rifle caliber for all missions.

Hmmm haven't had any hicccups with my Recon and 3,000+ rounds =/. I agree that 556 is definitely easier on the supply side of things

[LittleLebowski]

So now I'm gonna throw everyone for a loop,what about a reliable g2 recon in .308 with a muzzlebrake in a 16" barrel? More food for thought,curious to see everyone's input

There's a lot of better choices, at least to me. S&W, Colt, Larue, etc.