I recently purchased a complete 6.8 SPC rifle from a well known manufacture, out of respect and a current ongoing case, I will NOT state which one it was. I was very excited to order a “piston-driven” AR in 5.56mm. When I called to purchase the rifle on a department letter head I was talked into a 6.8 SPC by a tech at their company. I was told it was “Just as accurate if not more, plus more knock down power.” I was a little skeptical but having other 5.56mm it would help justify the new purchase. I read some online and several people praise the 6.8 SPC. So this problem is for them I guess. I started with Remington 115 grain MC rounds, shooting from a table and chair, using a Caldwell rest. Distance was an easy 100 yards. While for the most part I could hit the B-27 (human silhouette) after turning the sight aperture knobs some, I just could not get a consistent group. I was shooting 3 shot groups. I quickly stopped worrying about zero and started focusing on turning out a tight group. Most averaged roughly 6 inches at 100 yards. Best group was just under 4 inches when I moved up to 75 yards. I even tried using a brand new from an Aim-point Dealer that Aim-point personally recommended CompM4. Still, no better. I also tried Hornady 110 grain V max, groupings seem to get more consistently tighter, but still no better than slightly under 4 inches. I felt like I was shooting an AK-47 as far as accuracy goes. So I called the company and after saying its probably me, and I told them my friend who also had a 6.8 SPC in another manufacture, couldn’t do any better they told me to send it in and they would look at it. What do y’all think? Bad gun, bad ammo, or is 6.8 SPC a just not an accurate round? Should I ask for the 5.56mm? With the letter head I am not suppose to ever sell the “lower”. My point is, if I can’t hit the target consistently like I can with my 5.56mm, who cares if it has more knock down power? Thanks for all who answer, and please lets not start the 6.8 SPC vs. 6.5 Grendal debate. I want to know about the accuracy of the 6.8 SPC vs. 5.56mm. Thanks!
There is no reason a 6.8 would be less accurate than a 5.56 with equal ammo. You have a problem with ammo or a problem with a rifle/barrel not problem with the caliber.
The Rem FMJ has not been accurate at all from what I have shot.
FIX YOUR FONT!!!
I heard that also about the Rem, but the Hornady didn’t do any better. So maybe its a rifle problem? How accurate could one expect using a high powered scope and a bench rest? 1 inch?
Have the following rifles: Complete Barrett, LWRCi, and LMT rifles in 6.8 and all shoots 1 MOA or better with reloads with either the 110 grain Vmax and 115 grains SMK. With factory ammo–> 1.5 MOA is the norm.
Thanks thmpr, that is what I was told to expect from the 6.8 SPC. I had my buddy shoot the rifle too, to eliminate user error. I was in the Army Infantry, and he was a Marine Scout Sniper. So I guess it is not user error, but trying both rounds and not getting any better results, I wonder if the head spacing is off. The rifle functioned perfectly, no jams, no double feeds, as good as you could ask for, but I would be nervous to engage opposition forces at 100 yards. Not good for a SHTF rifle.
I have a Denny’s/WOA 18" barrel & shooting it with MBUS sites, I have a 5 shot group just breaking a nickle sized group& covered by a quarter at 50 yards.
I was shooting Hornady & SSA ammo
I still can’t believe show well it shoots especially since I was behind the trigger!
Your issue, I would bet is the gun & posibally the ammo .
I have got sub MOA results from several 6.8s I have owned
I honestly don’t expect 1/2" groups out of one consistently
but 3/4" is certainly doable
try a scope and some SSA Prohunter loads
they tend to shoot well in most guns
I was getting under 1.5" with a brand new Wilson Combat 16" with my handloaded Barnes 95g TTSX and a 1.5x ACOG TA44
and with an 18" WC all shots touching with a 3-9 Trijicon Accupoint and the same loads
all 100 yard groups of course
it’s not the cartridge itself…
My 16" (old Kotonics barrel) shoots MOA with SSA, Hornaday, and my reloads.
MadDog 
My first trip to the range, produced good results. How ever the trigger pull was so bad in compairson to my 1911s, I had a couple of stray shots.
Look around the net, you can find some info on “Barrel Breakin” give that a try. I’m trying it on my 6.8, so far it shoots quit well.
boy, that’s an easy fix 
Wilson Combat TTU
I have one and a WC 1911
I know what you mean by spoiled by good triggers!
Mailed it back today, lets see if they do the “right” thing and make it right. I told them they should just send me a 5.56mm since their 6.8mm SPC won’t shoot what they say. Word of advice, it doesn’t matter how many ARs you have, if you want another 5.56mm, get it, don’t let a salesman talk you into a 6.8mm SPC. Only get a 6.8 if that is what you truly seek. Now I know why the Military has NOT gone to the 6.8mm SPC. A $1900.00 rifle should shoot better than 4 inches at 75 yards from a bench rest. I should have bought a Ak-47 if I wanted crappy groupings a knock down power. 6.8 may have more knock down power, but if I can’t hit the target, who cares how bad ass it may be. If they don’t make this right, I will disclose their name so all of you can stay away from this company. Stay tuned!
Sorry your still having problems, hopefully your manufacture will make things right.
I made my 2nd range trip yesterday with my DPMS in 6.8. I swapped the red dot for for a Simmons 6.5x20, once it was sighted in, it would group 3 shots in well under an 1 1/2" at 100 yards. With a fresh target, I shot the last 10 rounds and had a group under 3". Changing the trigger springs made a big difference in pull weight. Not having a scale I don’t know the specs before and after, but the feel was like night and day.
I’m shooting Hornaday V max 110grs.
Do you know your twist rate?
1:10 twist416 Hammer Forged Machine Gun Grade Air Gauged Barrel
Ironfins,
I have been involved with government 6.8 mm development since early 2002; every good quality 6.8 mm rifle I am aware of has shot as well or BETTER than the equivalent 5.56 mm. There is something wrong with the rifle you received.
6.8 mm is an ideal LE round–I know some LE snipers that have not used their .308 bolt guns in nearly 2 years, as their 12" 6.8 mm Noveske rifles shot nearly as well and were far more versatile–allowing them to carry one rifle type for urban sniping, perimeter, entry, and Patrol duties.
My current favorite LE ammo includes the Hornady 110 gr OTM, SSA 85 gr TSX, and SSA 100 gr Accubond.
Thanks Doc, thats why I bought the 6.8mm SPC. Thinking of all the advantages. However being new to the 6.8, it was disappointing, especially spending $1900.00 with the dept. letterhead discount. Then burning over $150.00 in ammo and feeling like I have an expensive paper weight. What is really screwing me over is I am stuck. I have determined I don’t like the 6.8, judge the one I had, not all of them. But I don’t have the range time to go “play” with a rifle to get the bugs out, that’s why I bought a “top of the line” rifle. I need to zero, then start training with it. Now I know why my dept is such sticklers for ARs being a certain standard. With what I spent on the 6.8 plus ammo I could have bought a nice tier 1 rifle and used the “stockpile” of 5.56mm I already have. After this experience I am starting to doubt the benefit of the piston driven system. Maybe DI is better, at least I know that system works. I know anything man made can and probably will fail, however when I have a gun new and it fails I sell it. But I can’t this one, they screwed me if they send me a 6.8mm, I have heard I can change the upper, sell the 6.8 upper, and put a 5.56mm upper on the lower and it will fit perfect and not be sloppy. Since the serial number is only on the lower, would this be ok? I don’t want to violate the purchasing order I signed. BTW this company knocked about $975.00 off of the rifle, makes you wonder how bad they are screwing the civilians. After this experience I think I’ll spend my money on staying with military caliber ammo only. Then all I have to worry about is having some TAP rounds or other equivalent round. I am the only other person in my AO, besides my buddy who also shot the crappy rifle that has a 6.8mm. His Bushmaster was far more accurate than the brand I had. Ammo is still hard to find for me without going online. Before I bought it two stores in my AO stocked 6.8mm. I have been to 1 gunshow a month all over the state I live in and have only seen 3 boxes of Remington and 2 boxes of Hornady. It just doesn’t seem like the 6.8mm is catching on, or is very desirable in my AO. Once this nightmare is over I don’t see myself venturing out into AR caliber extacy anytime soon.
I just read a review of a Stag model 7 in a magazine in WallyWorld, while the wife was shopping (can’t remember which mag.) Of the half dozen or so 6.8SPC rounds they tried, most were 1.5 MOA or less. Several of the SSA rounds had 1/2in groups.
I’m personally waiting for my outdoor range to open, so I can sight in my Stag model 5. I have a pile of SSA Speer 90gr TNT and Sierra 110gr ProHunter to try out, along with a box of Hornaday VMax.
I am sorry for what you are going through–keep in mind, it is the fault of the rifle vendor, not the cartridge.
6.8 mm has offered better terminal performance and intermediate barrier capability than all other assault rifle cartridges in every test I am aware of that has been conducted since 2002. It brings the AR15 to a new level of capability approaching that of .308, but in a more compact, lighter configuration.
It is perfectly acceptable to put other caliber uppers on your lower–in fact, most organizations I know that use 6.8 mm also run identically set-up 5.56 mm uppers for training and reserve the 6.8 mm uppers for duty use (after appropriate zeroing and function verification).
We order all our 6.8 mm direct from Hornady and SSA–we never purchase it locally.
Well done civilian 6.8 mm testing recorded very good performance from the various vendors’ uppers: http://www.ar15.com/forums/topic.html?b=3&f=12&t=353523
The following superb quotes from another thread regarding pistons pretty much sum up what needs to be said:
[i]"They have dubious benefits especially in a carbine length gun. The only time they might be beneficial is if you are:
- Using a short length gun 10~11"
- Using a silencer
- Heavy amounts of rapid fire, like 1000 rounds a day heavy fire
If you cannot answer yes to at least 2 from this list, you do not need a piston"[/i]
I agree with most that it’s NOT the caliber itself. I have seen most 6.8 SPC’s shoot 1.5" or better at 100 yards. If it were me I proabably would have tried a couple more brands of ammo before shipping it back considering if it still shot bad it would just help your case. It definately sounds like a a bad barrel ie, maybe rough barrel, damaged crown, or something of that nature. Don’t ve hesitant of the 6.8 SPC cause it is a great round. Hopefully Vendor makes it right.
Thanks for the replys, I shot the Remington and Hornady loads because I called and talked to two different techs on separate occasions that recommended those rounds over any other. I asked about Silver State and they said they were good, but the Rem and Horn were what they shot in their own personal 6.8s. I hope it is the rifle, but being new to 6.8 it doesn’t help my confidence to have problems early on. Now as far as function of the rifle it cycled perfectly, no jams, double feeds, or delayed timing. I might have to sit the 6.8 crusade out until better ammo or more people in my AO have good experiences. I could deal with finding the best load on a bolt gun, but for a semi auto I think most factory loads should perform at least marginally well. I can’t start my next project till this is done, not sure what it will cost me to fix the situation. Oh now the wait for them to call me…