The first thing I would do is mount another scope and make sure it's rock tight, that would at least eliminate the scope as the problem. I have had shooting bouts like your saying and tightened everything up even more and they started shooting good.

 

I agree. My gut call on this would be the scope and/or scope mount, but most likely the scope.

Try another scope, or even just the irons, just to make sure it's not the rifle itself.

If you don't mind me asking, what's your barrel set up? Is it 1/11, or 1/10? Does Barrett mark/stamp the barrels with the rifling type?

I'm waiting on a REC-7 upper to come in that I ordered recently. I know they used to be 1/10, but now Barrett's web site shows them as 1/11.

Hope you get everything sorted out with yours!

 

Is it a milspec trigger = lots of creep and a heavy trigger pull? Could be an issue if you're used to a better trigger on the BA guns. SSA just put some more ammo on sale- factory 2nd's if you need to order some more. GTG Ammo is another source as well. If you don't have another scope then try sighting in at 50m with some iron sights to eliminate the scope and/or mounts as the issues. Check for anything loose - gas block, muzzle break or flash suppressor, etc. I was seeing sub-MOA with my setup and factory SSA OTM rounds during my 1st time at the range.

 

Your rifle should be capable of better than that, even with a rough trigger so long as you do your part. As said, check your optics, maybe something is bad. Your mount isn't bridging the gap between the receiver and forearm rail? Then, verify your rifle is solid (barrel tight, muzzle device tight, etc). Good luck!

 

My recommendation is a little different. Take off the scope if you've got iron sights and try the iron sights at 25 yards to see what happens. If that works, then have the scope mounted professionally by a gunsmith that knows what they're doing (not just a put the rings on and slap the scope in operation). That should fix it.

BTW, I use Lellier & Bellot 110 grain with my Thomson Center Arms Contender Carbine (16" bbl) and shoot dime/quarter size groups at 100 yards - so the ammo is pretty good in my opinion.

 

I have a few of the nikon M223 mounts and on both of them I had to torque them tighter than they say in the directions. I can't remember the settings or what they call for without going through my files, but I will try to look and see what torque I set them on. Seems like it was 5-10 inch pounds more than required. I always take a needle and make a tiny mark on my scope next to one of the rings in both X and Y directions. This is to show if there is any movement. In both nikon mounts the scopes slid forward about 1/8 inch after about 20 or 30 rounds when torqued to nikons spec. hope this helps. I don't know if you used a torque wrench or not to install your optics/mount, but if not it does make a difference.

 

And take the sled next time. I would sure put it on a sled (Especially if you already own one) before I bought anything other than more ammo.

 

The twist on my Rec7 is 1/10 - I have A.R.M.S. Iron Sights - but I haven't even sighted them in. The scope is mounted pretty solid - and the scope is what I have to live with for a while.. the Trigger is the factory trigger and the pull is significant. I've had similar problems before with a Remington 700 SPS Tactical in .308 - I changed the stock to HS Precision, had a muzzle brake installed, and had a 3 lb trigger job done and ended up at about 1/2"/ 1/2 MOA at 100 yds.. So I'm thinking that I'm going to try the trigger first.. but I appreciate all of the information. I can live with 1 MOA for an AR Platform rifle - I'm not expecting precision rifle accuracy, but 3" or worse is not going to cut it especially when I could've spent $600 on a Rem 700 and a Leupold M4 and had $1000 leftover.. That's what makes me angry.. Anyway - thank you for all of the advice - I'll check everything out and see if anything is loose..

Also - 68WJ - My scope is mounted on the upper receiver with the eye piece directly over the stock mount.


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Looks like your scope is touching your rear iron? May just be the picture, But if it is that may cause your accuracy problems. Also. 1 MOA is good for the AR, but some of the guys here have their 6.8s shooting .5 MoA or better @ 100 yards. So don't let that "a semi auto isnt as accurate as a bolt gun" saying fool ya. That is a real nice looking rig ya got there.

 

I agree, you should be displeased with those results... especially for the amount of money you shelled out for it. Merely for a point of reference... my 16" barrelled 6.8 AR (back when I had the Mil-Spec DPMS trigger parts in it) has delivered a best yet of .423" (6 shot) group at 100yds. And, I paid about 1/3 of what you did for mine.

I gotta agree with the others' comments on ruling out a scope issue to begin with. Is the crown damaged?

 

Somethings not right, once on paper all of that ammo should have impacted within a couple inches of one another, I say the scope is bad or it's not mounted properly, that rifle should shoot 1" or better at 100 yards easy.

Try some of the Hornady 110gr BTHP ammo, it's about the best shooting factory ammo you can buy. SSA's 115gr OTM and GTG's 115gr OTM ammo is great also, it's best to use known accurate ammo when trouble shooting and not rounds like the TSX that only shoot good in some rifles.

 

Somethings not right, once on paper all of that ammo should have impacted within a couple inches of one another, I say the scope is bad or it's not mounted properly, that rifle should shoot 1" or better at 100 yards easy.

Try some of the Hornady 110gr BTHP ammo, it's about the best shooting factory ammo you can buy. SSA's 115gr OTM and GTG's 115gr OTM ammo is great also, it's best to use known accurate ammo when trouble shooting and not rounds like the TSX that only shoot good in some rifles.

I agree. I had horrible results with the S&B, and the Hornady V-max wasn't much better. My ARP really likes SSA 110gr ProHunters, and I have a 250rd box of SSA 115gr OTMs and some Hornady 110gr BTHP ammo to try the next time I get out to the range.

Also, if you were on paper with the 110gr loads, no there's no guarantee the 85gr TSXs would be anywhere close at 100yds.

 

I agree with the 2 posts before me. My 16" Bison Armory didn't like the Sellier and Bellot either and I was disappointed as well. But once I started shooting Hornady (not A-max) and SSA, the groups shrank quickly. If I remember correctly, it also took a good 40-50 rounds for my rifle to settle in. I now shoot SSA 115 grain OTM's and Hornady 120 grain SST's and get fantastic results. I shot a 3-gun match with my 6.8 this past weekend and used Good To Go's ammo (1st batch) and had good results as well.

Check the scope and get some good, known accurate ammo and be patient. I stay away from Sellier & Bellot and Remington.

 

If I remember correctly, it also took a good 40-50 rounds for my rifle to settle in.

Found this to be the case with my BHW barrel as well... Shot sub-MOA afterwards with SSA 115gr OTM. Plus my weapon breakin process involves function testing, resolving any component fitment/compatibility issues(bad AR Stoner mags causing FTF for instance), MB tuning(12 port ITS tunable break), getting comfortable with the AR and sand bags on a bench... personally took me a bit of shooting to transition from a dozen years of BA rifle bench work to AR. By 60 or so rounds things settled down including the shooter(yours truly) and sub-MOA insued. That's a high $$$ Barrett you have so I would expect nothing but MOA or less out of it provided you've considered all the comments/suggestions already provided above by others on this forum.

 

If the groups are that big, then I would move the target in some, to say 50 yards, until you are comfortable. Then move the target out.

 

Another possibility is the barrel might be misaligned.
I don't know much about that. But, I hear it can trow groups off. Some others here know more than I do about it. I think H had a sticky on it?

 

OK, this is how it looks to me:

1st check everything because it's the logical thing to do... But, it sounds like the man knows how to shoot and mount a scope.

It sounds like a barrel or the way it's mounted.

 

When things shoot that bad it is usually because something is loose(scope mount or barrel nut) or the bullets may be contacting the inside of the muzzle device.
I had 2 LEO's from Chattanooga who mounted 1 scope ring on the receiver and one on the handguard...yeah that caused a problem.
recently a cracked scope mount...
broken barrel nut on a Troy/VTAC extreme rail...

Some rifles are overgassed and moving the carrier before the bullet leaves the bore, that leads to bad accuracy.
Also a very bad crown, have seen several hammer forged barrels that were cut with a dull bit, so bad the lands were mashed over into the groove. $320 barrels with crowns that bad=NO inspection at all

 

That's a bummer with such a nice carbine. Do you have another scope to try after you have first checked the mount? I have a couple of those Buckmasters (4.5x14 & 6x18) and I have been pretty happy with them, but it could have gone nuts on ya. My 6x18 took a good bump when my rifle feel over on a tile floor, and that thing went haywire. It's as bad as or worse then what you have mentioned.

 

1st,This was mentioned before. I think that scope is sitting on top of the flip up rear sight. It if is touching, its too close.
2nd, the barrel is chrome lined. You need to shoot the living **** out of it to break it in. It needs to get hot! Chrome lining is not precise and can vary in thickness by a couple thousands of an inch from the chamber to the muzzle.
3rd, you are excited. make sure you use a very stable rest when you shoot next time. Pull on the strap attached to the front lug to eliminate any slop in the receiver during recoil or get a Accuwedge ($5). Also, if there is any slop in the buttstock/buffer tube, remove the stock from the buffer tube, put a small strip of electric tape against the length of the buffer and slide the stock back on. I have done this to a couple rifles and it works great. Or you can just slap on a lower with a full size stock if you have one available.

Just my .02 cents. Barrett makes a great product in my opinion, but since I build my own configurations for my purposes, I havent found a completely suitable rifle in their product line that I care to get into besides the M82A1.

this being said, I had the same issue with a chrome lined barrel in 5.56. I'll leave the manufacturers name out of it, but every manufacturer has this issue with chrome lining.

 

Okay - well I've been gone a few days - but wow - I really appreciate all of the good advice.. I've mounted many of my own scopes, just for starters and usually don't have a problem. Normally, Like I said before, I shoot precision bolt action rifles in .308 and I've had Buckmasters before, mounted on a Remington 673 Guide Rifle - got a black hawaiian sheep at 400 yds with it.. That Buckmaster - Guide Rifle combo would shoot better groups than a Remington 700 I had with an HS Precision thumbhole stock, trigger job, muzzle brake, badger bolt knob, and Leupold Mark 4 - also like I said before, I was a rifle expert in the military and I can get 1/2 inch groups with scopes I've mounted - BUT - Those rifles all have trick triggers with 3 lb or less trigger pull - so I'm not at all positive it isn't me.. I was frustrated with the trigger and it may be trigger pull - but it was All over the place, even when I felt I got a good trigger pull. I'm going to move it back to 50 or maybe even 25 yds just to zero and then move out to 100 - I'm also going to try to borrow or rent a shooting bench or vice - and I plan on getting a Wilson Combat or other aftermarket trigger - the trigger pull is clearly too heavy.

Another person asked about over-gassing - this is a piston system, so I shouldn't have that issue. The break in period may well be an issue and it is chrome lined all the way back to the action, so that may be a valid reason. I'll have to see if it gets better.

With regards to ammo - I am very limited - as I said, I plan to use this rifle for hunting and, I know this is ridiculous, but because of that, my ammo is limited - here in California where I plan to hunt, I cannot use ammo that contains lead - because the California Condor may end up eating my spent rounds, so I have to use all copper ammo - so my ammo is limited - I plan on sticking with the SSA 85 gr or 110 gr TSX and I'll zero that and stick to it. Never the less, I've never seen a rifle shoot off the paper from changing ammo..

The mount is a single piece Nikon M-223 mount with a forward cant and the rear of the scope is a mm off of the rear sight - although it may touch when fired, it's not touching now. I'll consider moving it forward or back to get it away from the flip up rear sight. But the rings themselves are solid and torqued down.

I don't see any issues with the brake or the crown inside.

I'm going to start with 25 & 50 yard shots change the trigger and get a vice and see if it changes.. It may be me secondary to the trigger pull - after that if I still have issues I'll consider a barrel swap or other issues.

One thing that did bother me is that the trigger is very basic and the buffer tube and stock are Commercial size which doesn't lead me to believe that they spared all expense to make a quality rifle. I was really surprised that the stock was commercial. But the forearm/handguard and iron sights are top quality and very comfortable - and reviews of the rifle have been nothing but excellent, even with the 1/10 twist.. So I'm torn.. I'll try to figure out what's wrong with either the rifle, the scope, the rings, or me - and hopefully keep the rifle - one thing is for sure - 3 MOA groups will not suffice for hunting - so something has to get fixed or replaced. I wanted to go hunting this weekend or next, now I'm not sure that I can and I spent over $200 in ammo last weekend that I can't afford to replace at this point - so my hunting is going to be delayed which makes me even more disappointed. Anyway - thank you for taking your time to read my petty complaints and personal issues - I really appreciate your time, consideration, and advice.. Have a great week.

 

Okay - well I've been gone a few days - but wow - I really appreciate all of the good advice.. I've mounted many of my own scopes, just for starters and usually don't have a problem. Normally, Like I said before, I shoot precision bolt action rifles in .308 and I've had Buckmasters before, mounted on a Remington 673 Guide Rifle - got a black hawaiian sheep at 400 yds with it.. That Buckmaster - Guide Rifle combo would shoot better groups than a Remington 700 I had with an HS Precision thumbhole stock, trigger job, muzzle brake, badger bolt knob, and Leupold Mark 4 - also like I said before, I was a rifle expert in the military and I can get 1/2 inch groups with scopes I've mounted - BUT - Those rifles all have trick triggers with 3 lb or less trigger pull - so I'm not at all positive it isn't me.. I was frustrated with the trigger and it may be trigger pull - but it was All over the place, even when I felt I got a good trigger pull. I'm going to move it back to 50 or maybe even 25 yds just to zero and then move out to 100 - I'm also going to try to borrow or rent a shooting bench or vice - and I plan on getting a Wilson Combat or other aftermarket trigger - the trigger pull is clearly too heavy.

Another person asked about over-gassing - this is a piston system, so I shouldn't have that issue. What? what makes you think that, pistons are easier to over gas than a DI. The break in period may well be an issue and it is chrome lined all the way back to the action, so that may be a valid reason. I'll have to see if it gets better.

With regards to ammo - I am very limited - as I said, I plan to use this rifle for hunting and, I know this is ridiculous, but because of that, my ammo is limited - here in California where I plan to hunt, I cannot use ammo that contains lead - because the California Condor may end up eating my spent rounds, so I have to use all copper ammo - so my ammo is limited - I plan on sticking with the SSA 85 gr or 110 gr TSX and I'll zero that and stick to it. Never the less, I've never seen a rifle shoot off the paper from changing ammo..

The mount is a single piece Nikon M-223 mount with a forward cant and the rear of the scope is a mm off of the rear sight - although it may touch when fired, it's not touching now. I'll consider moving it forward or back to get it away from the flip up rear sight. But the rings themselves are solid and torqued down.

I don't see any issues with the brake or the crown inside.

I'm going to start with 25 & 50 yard shots change the trigger and get a vice and see if it changes.. It may be me secondary to the trigger pull - after that if I still have issues I'll consider a barrel swap or other issues.

One thing that did bother me is that the trigger is very basic and the buffer tube and stock are Commercial size which doesn't lead me to believe that they spared all expense to make a quality rifle. I was really surprised that the stock was commercial. But the forearm/handguard and iron sights are top quality and very comfortable - and reviews of the rifle have been nothing but excellent, even with the 1/10 twist.. So I'm torn.. I'll try to figure out what's wrong with either the rifle, the scope, the rings, or me - and hopefully keep the rifle - one thing is for sure - 3 MOA groups will not suffice for hunting - so something has to get fixed or replaced. I wanted to go hunting this weekend or next, now I'm not sure that I can and I spent over $200 in ammo last weekend that I can't afford to replace at this point - so my hunting is going to be delayed which makes me even more disappointed. Anyway - thank you for taking your time to read my petty complaints and personal issues - I really appreciate your time, consideration, and advice.. Have a great week.

Checking the crown takes a decent magnification, better done with a borescope.

 

I was wondering about the piston too, I know Barrett has a solid reputation but anyone can make a mistake. Between the sensitivity of piston systems and the unique mechanics of the 6.8 compared to the 5.56 they might not have the timing quite right. If the action is cycling prematurely it could be causing inconsistencies.

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Correct me if I'm wrong but didn't Barrett start out with 6.8, adding 5.56 later?

 

Let someone else shoot and see if you get the same results. Remember KISS ( keep it simple stupid) you my be blinded by what happening.

 

Contact SSA and talk to them about their experiences with Barret rifles, they have used more brands of 6.8 rifles than anyone and know how their ammo preforms in most of them and which ones have the most problems. I'm sure they may can shed some light on this for you.

 

I let my brother in law shoot it as well - he go the same result - two good shots in a tight group and then a 3rd and/or 4th shot 2-3" away.. It was wierd.. Like I said though, maybe it's me and the trigger pull - I'll have to get to the range again to find out.. but I am tapped for ammo and funds right now, so it won't be for a few weeks..

the action felt smoother than any AR platform action I've ever experienced - you couldn't even tell it had cycled.. So if it is the piston or the timing, I couldn't feel it. It's the smoothest operating AR I've ever had.. but it's also the only Piston system I've ever had.. I loved the action and the operation of the rifle. Funny thing is, the guy next to me had a brand new LWRC and his rifle wouldn't even cycle the spent cartridge out of the chamber - he was having nothing but problems and LWRC is as expensive or more expensive than Barrett.. I was quite surprised, he said he was taking it back to the store..

I'll figure it out one way or another - thanks for all of the advice - I really hope it isn't the crown.. that would suck.. but replacing the barrel is something I eventually want to do anyway - I don't want a 16" barrel - that's too short for me and my application - so I can fix that.. I'm going to start with an aftermarket trigger and go from there. Hope all is well - have a great weekend.

 

I let my brother in law shoot it as well - he go the same result - two good shots in a tight group and then a 3rd and/or 4th shot 2-3" away.. It was wierd.. Like I said though, maybe it's me and the trigger pull - I'll have to get to the range again to find out.. but I am tapped for ammo and funds right now, so it won't be for a few weeks..

These results @ 50 yards?

 

Not trying to bash your rifle but for the money you could have got a much better rifle from Bison, ARP or Rainier. I never bought into the piston hype so I can't speak for that. DI works fine for me. If I did a lot of 3 gun fast fire stuff, the piston might be a little better.

That rifle would be in the mail now, on it's way back to Barrett. Hopefully they will get you up and running.