Grendel AR upper build vs bolt action accuracy

[Taz575]

I am looking into a 6.5 Grendel as a Coyote, Deer and Target shooting gun. I have a Howa 1500 308 and a CZ 527 Lux in .223, so I am familiar with the quirks of those rifles as well as the great accuracy. I also have Savage 10 Bolt Actions in 223 and 6.5 Creedmoor that can both shoot around 1/2" at 100 yds with handloads as well, so I like an accurate rifle! What would it take to build up an AR Upper with a similar level of accuracy as the others, ie something 1/2-3/4" at 100 yds with good handloads tuned to the rifle. Is this realistic to expect from a semi auto AR upper for under $800? Are there any advantages to a side charging handle vs the traditional AR upper in terms of accuracy? I was thinking of the BCM upper that you heat up to get a tight fit on the barrel extension, but I am open to suggestions to build up an accurate AR upper. I am looking at a 20" barrel for the AR if I go with the upper.

[Kswhitetails]

You can. Absolutely can. You have your bases covered, and as long as the barrel quality is of the right level or above, you should be able to garner your desired accuracy thresholds with some left over margin. I'd say that going from 3/4 moa to 1/2 moa in a decent barrel would be your hand load development.

Build wisely, obtain the highest quality parts you can afford. Good call with the BCM upper, although any other good billet set would do well. For supreme accuracy, a thermal fit as you describe above or bedding the barrel/extension is recommended. You're putting it together anyway, why not? Bed the block if it seems even remotely beneficial. Same with the feed ramp polish. Any competent BCG will work, if you decide to go LMOS, just ensure that you follow the 5.56 guidelines for the same systems. 20 inch barrels do best with rifle length gas, though some are different and report good results as well.

Just make sure you get the basic fit right, and a high end barrel and bolt. You'll be happy.

My recommendations would be either Bartlein, Lilja, or Proof. All seem to be pricey, but report consistent results in the area of your expectations. Mark with Precision Firearms is a good source for either of the Bart or Lil, but will delay you as he's busy, and popular - for a reason. If waiting isn't a problem, then look hard his way.

https://www.precisionfirearms.com/48m8/6-5-grendel-barrels.html

The other option as I see it, is the LaRue Ultimate Upper kit in Grendel. You get what you're looking for, and much more for about that budget. And while (SOME) of our fellow board members seem to think LaRue's barrels are "off the shellf", they prove the falsity in that with their performance. Take a look at the LaRue UU kit before you make your decision.

https://www.larue.com/products/larue-ultimate-ar-15-upper-kit/

Any way you choose to go, check in with questions. Someone here has done what you're doing at every step; and from my experience, you're likely to get good advice from competent do-ers vs keyboard warriors here.

You'll enjoy Grendel for your listed purposes. Welcome aboard, and keep us posted!

KS

[A5BLASTER]

Barrel, scope/mount and trigger spend the most money on those and the rifle should be capable of 1/2 groups at 100 yards.

But all that still depends on the shooter

[Klem]

Hi Taz, welcome,

1/2" grouping with a semi-auto is not impossible but needs to have one of the best available barrels. Throw in a decent scope and trigger and your $800 budget has blown out. The AR15 receiver is fairly light and flimsy compared to more solid bolt actions. It was designed this way for mass production with a military short-range provenance. Turning that into a gun that rivals what you already have is going to take a few dollars (unless you are extremely lucky with a cheaper barrel). Semi-auto's also require full-length sizing with COAL's restricted by the internal length of the magazine. This means you don't enjoy the accuracy benefits of fire forming cases and end up with longer than preferred bullet jumps. With an AR15 you are forgoing accuracy for a quick firing gun, i.e. more firepower. If there was no downside to semi-auto's then Bench Rest, F-Class and Target Rifle competition shooters would all be using them, and they don't.

Top quality barrels are around the $500 mark (e.g. Lilja). That does not leave much for the rest of the upper. You could buy a blown-out second hand upper and swap the barrel for a good one. Hopefully the upper is square with the barrel. You also need a mount and scope so I hope the cost of the scope was not in your original budget.

Or, you could stick with your budget and enjoy the utility of semi-auto in an efficient calibre. You won't get the same size groups as your bolt guns but if you qualify your expectations of accuracy where cheap semi-auto's are concerned you won't be disappointed.

[Kswhitetails]

No way the OP's expecting to build an upper and optic expecting sub .5s when including the optic and mount. That can't be done. Not realistically.

Maybe if someone gets lottery luck on a perfect cheap optic, perfect cheap barrel, and perfect cheap... wait.

Who was it that had a sigh somewhere... "You can have good, fast, and cheap. Pick two."?

[BCHunter]

The advantage of a side charger is for ease of use. If you ever tried to charge an AR with a big scope you would see why.

[Klem]

The advantage of a side charger is for ease of use. If you ever tried to charge an AR with a big scope you would see why.

Unless you use Ranier Raptor charge handle, or similar that can be operated from either side with one hand.

[biodsl]

What would it take to build up an AR Upper with a similar level of accuracy as the others, ie something 1/2-3/4" at 100 yds with good handloads tuned to the rifle. Is this realistic to expect from a semi auto AR upper for under $800?

I read this whole thread and would like to re-state what others have said but make sure it's clear: this requires a top tier barrel. There won't be much left over for an upper receiver, gas block, hand guard and bolt carrier group.

[Taz575]

Great info guys! I picked the $700 budget because I could buy either the CZ 527 or the Howa (and $$$ left over) and get a decent/nice trigger, nice accuracy and may have to do some minor tweaking, like I did when I bedded/pillared my 527 223. Like has been said, I won't get an upper of the same accuracy for that price and would have to upgrade the trigger as well (both triggers in my preban AR's are standard (bad) triggers when looking for accuracy!) I do have some decent optics/mounts left over from other guns I had, so I didn't include that in the price for now, just looking at the cost of the rifle/upper. Most aftermarket triggers are in the $150-$200 range, but I am not including that in the $700 budget. I don't shoot my 300BO upper very much at all, so I may sell that to help fund the project (AAC 16" complete upper with BCG) to get into a 6.5 Grendel. I do not have an accuracy setup for my AR's yet, so I figured the 6.5 Grendel would kill 2 birds with 1 stone!

I've seen built uppers from some places for around $500-$700, like Hardened Arms, Sanders, AR15parts.com and others, but I am guessing the quality may be suspect? The LaRue doesn't have a 20" 1:8 twist setup. I would rather build it myself with known components I think for the cost!

Looking at specing out a setup from JoeBob Outfitters for some comments:

Seekins Precisions Upper:

https://www.joeboboutfitters.com/Seekins-Precision-IRMT-3v3-Upper-includes-forward-p/skn-irmt-3v3.htm?CartID=4

15" handguard for upper:

https://www.joeboboutfitters.com/Seekins-Precision-SP3R-V3-M-LOK-Competition-Handgu-p/skn-sp3rv3-m-lok.htm?1=1&CartID=3

Faxon Match barrel and Odin Works Nitrided BCG (Or is the Odin Works 20" barrel better?):

https://www.joeboboutfitters.com/Faxon-Firearms-20-Heavy-Fluted-6-5-Grendel-Rifl-p/fax-15bg8r20fhq-5r-np3.htm?CartID=1

Looks to be around $830, plus another $100 for charging handle (I have a generic one at home from my 5.56, but would need a bigger ambi one to use with a scope), gas block and gas tube, so around $930 total. Going with a BCM Upper saves around $130 and brings it down to around $800. $930 isn't bad when I remember that the 300BO was $950 at Midway originally, but I got it on sale

What barrels are recommended in the $250-$450 range and what can be expected group wise from barrels in this price range? I know the best will be $500-$800 barrels, but what about in the mid range?

[Taz575]

Biodsl, I hear ya! What can I expect for accuracy out of a mid price range barrel? Like something in the $250-$450 range? Would 3/4-1" be reasonable at that price point or no?

I have extended/ambi charging handles on my AR's currently due to scopes on them (1-4 Burris MTAC, Vortex Strike Eagle 1-6), so I know the side charger would work better with scopes, but are there any advantages/disadvantages accuracy wise with the extra slot cut out of the receiver?

[hill37]

Wilson Combat has a fluted 18" or 20" crowned and fluted stainless Hunter barrel for about $325. The matching BCG is high though,$300.

[biodsl]

Biodsl, I hear ya! What can I expect for accuracy out of a mid price range barrel? Like something in the $250-$450 range? Would 3/4-1" be reasonable at that price point or no?

I've owned four barrels from Sabre Defense, Lilja, Black Hole Weaponry and Alexander Arms. Each would shoot 1moa three shot groups. Sometimes .7, sometimes 1.0. Five shot groups usually hover around 1moa. The reason is the shooter and not the barrels. You'd think the Lilja would have shot best but obviously the guy pulling the trigger is not up to the task.

I had a Remington 700 tactical that I shot well. It was a sub-minute rifle when fed Gold Metal Match ammo. I don't get those results with my Grendels. I've still not mastered the technique of an AR. I personally can't exploit the accuracy than top tier barrels offer at this point. My money is probably better spent on ammo.

Many mid-tier Grendel barrels shoot 3 round sub-minute groups. Some come with a guarantee. If you can be satisfied with that a $200-$300 barrel should suffice.

[Klem]

You could strip down that 300BO. Set aside the barrel, bolt and gas tube. Use the rest with a longer gas tube, Grendel bolt and new barrel. You will be able to almost guarantee sub-moa-3rd gps if you can reload and have a decent scope, trigger and stable shooting platform.

[Bigs28]

Larue mbt is under $100

Radian raptor I've seen on sale for under $50

[Zeus]

TRUE (meaning not once in a while) 1/2" factory rifles are all over the internet......but rare in real life.....and that's for bolt action rifles....Even tougher to build a gasser with that level of accuracy. You're gonna spend some dough to make it happen.

Your getting good advice about the barrels that you're going to need to get there. Stick with the top tier brands and you have a chance of attaining your goal. Mag length restrictions and reliable feeding are also things to take into consideration when doing load work-ups for an AR style rifle.....lots more going on than with a turn-bolt.