Hi everyone,

I purchased a larue complete upper receiver group last year for a prairie dog hunt I had scheduled. I went with this upper because it uses their stealth barrel and they had advertised easily shooting sub MOA groups with factory match ammo (claimed .4 MOA at 100 yards with hornady 75gr match). I also ordered it because the price point was appealing at $750 or so (before the price hike).

I have not been able to get any respectable groups out of the thing. I have tried all sorts of match ammunition including but not limited to Nosler match 75 gr, hornady match 75 gr, sierra match king 77 gr, Hornady ELD-X, I tried some lighter match bullets as well. Nothing seems to be capable of “easily” sub MOA. The best I’ve had was maybe MOA with the match kings but even that was rare to the point I would call it a stroke of luck. I’m shooting supported with bags under good environmental conditions. I am capable of shooting sub MOA groups and do it often with my bolt guns. The reason for giving it some time before posting is I figured maybe I had to shoot it more, or try “just one more type of ammo.”

I removed the hand guard to check the barrel nut tightness and go figure my wrench doesn’t seem to line up with the nut grooves. It does appear to be tight, although, I’m unsure as to the actual torque specs it should be at (I’ve never fully assembled every part of an AR before). I checked my ring tightness on the larue LT111 mount that I have a vortex venom 5-25x56 in. I know it’s not a Swarovski but I don’t believe it would be the issue. The scope mount is rock solid and returns right back to zero after removal and reinstall. I did add a Riflespeed adjustable gas block for shooting suppressed and have it tuned 1 click above intermittent bolt catch operation. It groups the same (poorly) as it did with the original gas block. It groups the same whether or not it’s suppressed or unsuppressed and I’m using a SureFire closed tine flash hider (not the warcomp version with 12 O’clock gas ports). I really don’t want to test it without the flash hider as I have it rockset in place and I can’t imagine that being the issue.

Any idea as to how I can get these groups to tighten up? Or did I simply get a dud? Anyone dealt with larue customer service? I’m sort of afraid to contact them after my horrible athlon optics customer service experience. Do you think they would blame me for removing their flash hider and gas system?

I was really hoping to try out some federal premium Nosler partitions on deer with this thing, but the only way I could ethically use such a small caliber is if it was dead nuts on. I was getting like 8 inch groups at 200 yard with them and my personal requirements would be at least half that. Lots of prairie dogs survived to die another day because of this rifle.

Thank you for any advice you can provide.

A. try a different ammo
B. contact Mark LaRue

It did not

My ultimate upper in 6.5 grendel had problems grouping,after removing the brake , I saw a defect on the land. Sent it back to them  and they put almost all new parts except handguard. Problem solved. Sometimes these things slip by, this upper was a couple years old by then and they took care of it. Customer service was excellent.

How many rounds does it have down it? What kind of stock do you have on it? Some stocks are better than others on bags. Most of the wedge ones suck .
Have you tried off a bipod? Even a cheap cvlife bipod from Amazon works better for ARs than bags for me.
Back to the round count. I ask that because I have a WOA barrel I was really disappointed in. After 150 rounds I fully expected it to be broke In but it was terrible. To say I was disappointed was an understatement. I even emailed WOA. They said I could send it back but I just never got around to it  I just considered it a disappointing plinker after that. Swore I would never buy another WOA anything.
I'm a reloader and am always trying different loads out of boredom and well, just because.
At about 400 rounds I started seeing good groups out of it. I was very surprised. They just kept getting better and better  Now it shoots awesome.
I would've never dreamed it would've took that many rounds for it to break in. I've had barrels that would shoot awesome from round 1 and some that took 150 or so rounds. After that I figured they aren't going to shoot.  But 400 seemed out there.
Magpul makes a stock I think called PRS lite that isnt bad off bags. It's more rectangular and isn't as expensive as their more expensive option.

A few things come to mind. I’m sure Larue has put out a bad barrel so it’s entirely possible, but…

1. Just because you can shoot sub moa with a bolt gun does not mean it applies to a gas gun. Gas guns are harder to shoot accurately so it very well could be shooter error.

2. QD mounts are not known for tight lockup, they don’t clamp anywhere near as tight as a torqued cross bolt or nut. You may see it as a solid mount, but I don’t nor do most other precision rifle shooters who have experience with them.

3. The optic. It’s a low grade chinesium optic, not known for reliable performance.

4. I didn’t see where you mentioned what lower you’re using. Is it a decent lower with a good fit, a good trigger, and stock? You’re not going to slap a good upper on a sloppy lower with a heavy GI trigger and go shoot tight groups.


I would shoot it with another optic and mount that is better quality and known to produce good groups on another rifle and also have someone else shoot it. Also pick up a bit of FGMM 77gr and try it, that’s the gold standard for accuracy testing.

I personally have two of the MGU’s and both of them are absolute hammers. Both of mine are on LMT lowers that fit nice and tight with Larue triggers and Japanese Eotech Vudu’s mounted in Spuhr mounts.

Larue makes some of the most accurate AR barrels I have shot, They get some flack for their marketing and some of the other things they do and I get it. I have none currently but again have had about 4 and have a buddy with a predatobr that shoots like a bolt gun. Their customer service is excellent If for some reason it is defective I'm sure they will take care of you. Send it in.

I'm not a larue fan boy by any stretch but I'll be the first to say that their MBT's are great for what they are.  They ain't no HSNM, but for a very affordable 2 stage trigger, it's awesome.  

I have 4 of his barrels (3 20 inch 223 wyldes and 1 224 valkrie).  2 of the wyldes and the valkyrie both shoot sub .4 moa.  The other wylde I literally just pit in a new build and haven't taken it out...but I don't see why it wouldn't do the same as the other 2.

Consistently?

I’ve had several LT barrels, and a few have been sub moa. None have been sub half moa. The closest one is my 6.5creed UU, and it’s more of a 0.6-0.7moa shooter with handloads/ factory ammo it really likes.

I’m sure some barrels shoot, but I wouldn’t ever purchase a LaRue barrel and expect it to be a half moa performer. Do some do it? Probably. Do most, not in my experience. Kind of like Ballistic Advantage. Oddly enough, my Ballistic Advantage 6.5creed barrel has shot tighter groups than my LaRue.

Also OP, seeing a few cherry picked 3 shot groups is marketing, not objective evidence of what the barrels will typically do, especially with factory ammo. There’s just too much variability that isn’t captured in 3 shot groups.

Both of mine are sub 1/2moa with 77gr Berger OTM habdloads. They’re sub 3/4moa with 77gr FGMM, 77gr Norma, 77gr Federal LE TMK, and 55gr Federal LE 55gr SGK. AE223 55gr bulk is 1-1.25MOA. 5 shot groups, not cherry picked.

They’re two of the most accurate factory uppers I’ve ever owned. The only factory upper that has shot even better was an old RRA varmint and a KAC Mod 1.

Do you have any 5x5 groups with those uppers?

No, I don’t waste ammo shooting 5x5’s at 100 yards when I’ve seen what a rifle is capable of. They get one or two 5rd groups shot occasionally at 100 to confirm zero and that’s how they shoot every time.

A couple questions:

Have you run the scope setup on another ar with known accuracy? Need to eliminate scope as a contributing factor.

Are you shooting a carbine setup and which stock? Some carbine stocks are fairly loose and difficult to be consistent with.

What trigger are you running. A good trigger is important.

We’re the 77smk’s factory or hand loads? Factory is consistent but not always the most accurate.

Have you had someone experienced with shooting AR’s for accuracy shoot it? Need to eliminate the loose nut behind the stock.

If you go through the process to eliminate the contributing factors and it still won’t shoot to your liking contact LaRue about it.

I had one stealth upper that was not consistent so I contacted them about it. The first question was what my experience was and the second was what ammo I was using. I am experienced shooting for accuracy, multiple MOA entries, so they had me buy some factory smk’s and shoot groups and send them in. When they saw the groups they had me ship it back. I got it back about a month later and it shot lights out. Don’t know what they did but it was fixed.

They have also had people return uppers that when shot at LT they were in spec. They have also had people return uppers that had been modified which were rejected because of the mods. If you have to send it back make sure it is in factory original condition and that it still doesn’t shoot in that condition.

Shit happens in manufacturing. When it does happen sometimes it takes time to figure it out but a good company will stand behind its work.

To my surprise, the valkyrie barrel is very consistent.  The 223 wylde barrels are pretty solid for the most part.  If we r being honest, sub 500 yards its pretty consistent as well.  Anything past 600 it does....ok.  but I just blame the fact thst I mostly use 75gr hpbt and not 77 smk/tmks.

....

???

I guess you didn't have as good of results?  I know larue barrels aren't crazy match quality but they don't suck either.  I have a few JP barrels as well and those are amazing shooters as well.  But again, finding the load for each barrel is alittle time consuming.   The hardest part (for any barrel) is finding a load that works well with it.  But I also go over kill with brass prep where most people just clean and load and get excited if they get moa or thst random 1/2 moa group here and there.

Your rifles are not .4 MOA performers.

Go shoot a few back-to back 5-tound or 10-round groups with your overkill brass prepped ammo and post the pics. I assure you, the groups will be far from sub .4 MOA.

Below is an example of two back-to back 10-shot groups... I doubt your rifles will duplicate these groups.

I have several LaRue rifles, none of them are .4 MOA with me shooting them; however, I can manage back-to-back 0.75-0.80 MOA with 77gr SMK 556 in an 18" barrel, and Hornady Black (ELD-M) 123gr 6.5G in an 18" barrel when I'm doing my part. My best is with the 18" 5.56 at 0.600 on a day where there was no wind.  I've not been able to get that with the Grendel, but I admittedly do not shoot it as much.  I think 0.400 would simply be sheer luck, not to be repeated back to back. I probably average about MOA with both, well within my use cases. I shoot suppressed with a SilencerCo Omega 300 hanging off the end of each. To say I'm happy with MOA is an understatement given what else I observe at the range.

A previous poster is right, gas guns are just different. I notice it immediately if I don't shoot one for a while that it takes a minute before I can shrink groups down, and I know it's me - not the equipment. But to that end, I harvest deer reliably with both 556 and 6.5G with 0.0 drama based purely on shot selection and placement.

All that being said, if I don't put the .556 endcap on that omega 300, the groups expand. I wouldn't think it mattered, but it sure does.

When Larue stopped using Lothar Walther barrel blanks is when Larue stopped being a consistent performer.

Are there even any factory loads that would claim 0.4 MOA??  Sub-MOA sure, plenty of factor load and barrel combinations capable of it these days.  I like (liked before the price changes) Larue barrels when they were on sale and while Mark posts some outlandish shit, I dont think they claim 0.4 MOA with factory loads.

No.  If you were able to get repeatable .4MOA 10rd groups from factory ammo; it was pure luck.  Once you shot your box, you'd hope you've got a case from the same lot#.

Even high end factory ammo isn't consistent enough in terms of powder charge, neck tension, case wall thickness, etc. etc.



OP: My stealth barrel is an average performer.  With FGMM 77grSMK I typically get right around 1.25-1.5"" 10rd groups.  Not great, not terrible.  For the $200 paid, it's ok.

I've had good luck with LaRue uppers.  Was just shooting the one I bought a few months ago on sale from LaRue this morning.  Upper is supposedly NOS Mark found lying around.

18" upper with Burris 18x scope in a LaRue mount.  Mated with an Aeroprecision lower with an MBT trigger and PRS stock.  Shooting off a bipod with a newly installed Nomad TI suppressor I was getting good accuracy - i.e. the following 5 shot groups at 100 yards:

.9"
.9"
.9"
1.0"
1.25"

That's with AAC 77gr SMK factory loads.  And honestly I feel that a better shooter would be able to shrink those groups at least a little.

Then started shooting steel at 200.  Was very please when I went 9/10 at a 2" steel plate at 200 yards.

That's pretty much as good as I can do with an AR.  Can generally tighten things up a little with a bolt gun.

Have had a couple of other LaRue uppers as well, that I purchased a number of years ago.  All were 1-1.4" shooters in my hands, again with factory ammo.

So I'm not getting .4 MOA 10 shot groups .  But approx. 1 MOA is more than adequate for any shooting I plan to do, particularly since when I get out to 4-500 yards with these rifles reading and adjusting for the wind is going to be a lot more of a factor than whether my rifle is .8 or 1.1 MOA at 100 yards.