6.8 hunting performance and upper selection

[Trapper458]

Greetings all,
I currently hunt with an AR-10 in 7mm-08. I have the Rem R-25 and like it, but am considering a 6.8x43 (SPC) for a lighter weight rifle. I mainly hunt whitetails and mulies shots usually run under 300 yds with a once in a while longer shot. With the current availability of good lighter weight hunting bullets, I'm wondering what performance you are getting from your hunting rounds in terms of velocity and actual performance on Deer sized game. I'm considering the 18"-20" uppers from Bison (20"), ARP (18") and Stag 7h (20.77), and probably the more basic models with the free float handguard. I plan to initially mount the upper on my Bushmaster lower with a JP enterprises FCG which I like very much. If you could comment on:
--weapon, barrel length, load, bullet, velocity, + comments on bullet performance
--weapon, weight, configuration--(scope, magazine included in weight, #rounds, etc)
--the + and - of my described options, and any other uppers I might consider.
Thanks, Trapper458

[shjelm]

You will not be disappointed with your choice of a 6.8. I love my 16 inch bison. Very accurate .5 - .75inch all day, 29.5 gr H322 SPH 110. Very easy to carry in the woods, 7.5lbs with scope. Velocity around 2500 -2550. Two shots and two deer this season. My new go to rifle for deer.

[ArtFWTx]

Look through the hunting section. Pretty much says it all. Deer and large wild pig fall easily to the 6.8. Hunters who are AR fans love the 6.8. Most of the ammo offerings include very well known hunting bullets... Prohunter, TSX, TTSX, Accubond, TNT, VMAX, SST, and GMX coming soon to a theater near you.

16 inch barrels offer all the performance you're after. You only give up 50fps give or take to go with the handier/lighter 16 inch barrels.

I like the 18 inch barrels, but keep coming back to you can do the "same" things with the 16" barrels. So include the 16" barrels in your shopping. Get the longer barrel if you want, but if you're after weight to performance, the 16" recons out there shine in this role.

[Ratdog68]

Welcome to ya... and, +1 the input from others concerning the consideration of the 16" rig. The 6.8 shines in the shorter length barrels. The Stag 68s seem to be a roll of the dice (since they do not have the m4 feed ramps). Some of them feed fine, others don't. How do you know which you're gonna get? You're gonna get a fine rig with one of the sponsoring vendors' offerings... with all the good specs. I opted for the ARP 16" full float upper for mine. Couldn't be happier with my set-up. Now, if I could just get that loose nut behind the stock properly adjusted.

[John A.]

Funny how great minds think alike. I was wondering the same thing about barrel length so I'm glad I saw this post.

I looked on wikipedia before joining and couldn't find a lot of info between velocities between the 16 and 20 inch barrels. The biggest difference that I have seen is the 16 inch barrels are more expensive. At least the DPMS barrels are on midways website. Now if I could just find out if they have M4 feedramps because the DSA upper I am going to use does and I don't want to mix/match anything at the chamber.

I was thinking I would opt for the 20 inch barrel mostly for cost savings. Plus, I don't own an AR with a rifle length barrel. And if I could squeeze a few more FPS out of it isn't entirely bad either.

I varmint hunt with a 16 inch barrel, but I don't think the extra weight of 4 more inches of barrel is going to kill me.

[ArtFWTx]

Buy what you want, but keep in mind the 6.8 was designed for carbine use in military applications. It just doesn't need a long barrel to achieve it's effectiveness. If a 16 inch barrel will launch a SSA 85 TSX bullet at 3000 feet per second, and a 20 will not do much better you'll see why 90%+ of 6.8 barrels are 16 inchers. The original post talked about a lightweight rig... 16" recon style barrels are just that without any compromises in performance.

There are much better barrels than DPMS by the way. Their 20 inch 6.8 barrels are probably cheaper because they do not sell well. If you already have it, okay. IF you're still shopping look at ARP, Bison, Wilson Combat. Of the production barrels, Armalite's new barrels look solid with good specs.

[John A.]

I'm still window shopping. Some of the reason I was looking at the DPMS was I've never heard of ARP or Bison. I've been around AR's for years and it's a first.

I'd already spoken with DPMS and they said they had the 1:11 twist and SPC II chamber. So that's supposed to be alright. I'm just not sure which barrel extension they have whether it's M4 feedramps or standard/rifle and I think with the larger diameter bullet I'd rather have an M4 extension. The upper that I am going to use is a DSA, and it has the M4 notches, so I would insist on the barrel having the same.

And I also like the barrel being threaded 1/2-28 instead of everyone elses' 5/8 or whatever it is. Mostly because I would've had it cut and rethreaded because all my other stuff is threaded for 1/2-28, or if not rethreaded, would've had TROS make another thread adapter for me. So either way that's important to me and it's just easier to buy it the way I want it to begin with.

Are the ARP and Bison barrels that much better? In terms of feed/function and accuracy? Price doesn't seem to be very different. If the Bison or ARP is "all that", I may consider them, but am still learning the ropes with the 6.8.

[tbready]

I'm still window shopping. Some of the reason I was looking at the DPMS was I've never heard of ARP or Bison. I've been around AR's for years and it's a first.

I'd already spoken with DPMS and they said they had the 1:11 twist and SPC II chamber. So that's supposed to be alright. I'm just not sure which barrel extension they have whether it's M4 feedramps or standard/rifle and I think with the larger diameter bullet I'd rather have an M4 extension. The upper that I am going to use is a DSA, and it has the M4 notches, so I would insist on the barrel having the same.

And I also like the barrel being threaded 1/2-28 instead of everyone elses' 5/8 or whatever it is. Mostly because I would've had it cut and rethreaded because all my other stuff is threaded for 1/2-28, or if not rethreaded, would've had TROS make another thread adapter for me. So either way that's important to me and it's just easier to buy it the way I want it to begin with.

Are the ARP and Bison barrels that much better? In terms of feed/function and accuracy? Price doesn't seem to be very different. If the Bison or ARP is "all that", I may consider them, but am still learning the ropes with the 6.8.

ARP and Bison are worlds better than DPMS. 5/8''-24 is usually standard on most 6.8 barrels.

[ArtFWTx]

Agree with tbready. ARP and Bison are heavily involved in the 6.8 and the best performance specs. Both companies and owners made an effort to offer the preferred performance specs ahead of the rest of the industry in the past few years. DPMS offers 6.8s because everyone else does. DPMS was one of the last companies to move to SPC II, plus they already had a reputation for too restrictive chambers. DPMS falls into the hobby gun category. You really should spend time reading up on who is who in the 6.8 world. Constructor and Carnaby know more about the 6.8 than anyone at DPMS.

Some of you lower post count, new to the 6.8 guys should spend some time in the docu database section. Here's a very good report to give you an idea where the 6.8 was a few years ago and where it has evolved into today.

http://68forums.com/forums/showthrea...ng-Report-2008

As to barrel threading in ARs, threading is caliber specific. 5/8-24 is standardized for 6.8 and 308 ARs. 1/2-28 is used on 5.56's. Some 6.8s from Stag and Yankee Hill offer 1/2-36 threads also used in 9mm ARs. The reason for the differences is obvious. Someone would thread a 22 caliber muzzle device on a 308 or 6.8 barrel and would be creating a muzzle obstruction which isn't a good thing. The word Kaboom comes to mind...... So if you've had trouble finding 1/2-28 6.8 muzzle devices, that's because that threading is standardized on 5.56 ARs.

[Equalizer_2]

Any muzzle device you want to use must have a bore that is safe to use with the larger diameter .277 bullets so the 1/2x28 thread on the muzzle is designed for .223 diameter devices is something you must watch out for.