Light weight but accurate AR15 (6ARC or 6.5 Grendel) barrel.

[RC51kid]

I am looking to build another 6.5 Grendel or 6 ARC. I have narrowed it down based on my needs but want input about barrel manufacturers.

I want it to be able to take mule deer and smalled under 200 yards. If it can be exceptionally accurate i could also use it for coyotes.

Rifle will be supressored so i want a stiff enough barrel to not have a massive POI shift if i need to take a shot unsuppessed. I want 14.5-16" since it will have a supressor on the end and i will be using this climbing through the woods. In open country i will use my Tikka. I would like it to be around 26-28oz barrel. Sub MOA would be nice. I would love to shoot bug holes but honestly 1 moa is just fine.

Info about POI shift. I did some testing the other day. My 14.5" 5.56 criterion CORE is a reasonably light barrel but with a good contour with 2 different supressors had about 2" poi shift vertically. This is acceptable to me. If i made a quick shot unsupressed i would still get a hit out to 100 yards.

My very light-weight 16" Grendel barrel with 2 different supressors had OVER 8" poi shift. Almost off the paper. This is totaly unacceptable to me. If i had to make a quivk shot without the supressor at 100 yards i would easily miss my animal.

I would preffer 16" for the little extra velocity and to avoid some SBR hassle.

14.5" wins becouse it is stiffer, lighter, shorter which matters with can hanging off the end. Velocity loss is minimal but still there. The lower us already a SBR so it isnt a big deal EXCEPT if i travel.

So the two barrel leangths both have proes and cons.

I know the easy answer is Proof Carbon. Maybe i will go that direction. But if i can avoid dropping $1100 it would be nice. Craddock RTR 14.5" Grendel fluted barrel is around $550 and 26.5oz. Checks almost all the boxes.
To summarize:
14.5-16"
26-28oz
1 MOA or better
Stiff enough for minimal POI shift

Then i wonder if some "budget" barrels like the Wilson Combat Recon at $270 would do just fine. If it is stiff enough and will give close to 1 moa groups it might work out.

JP 6 ARC barrels also look good. But the profile is strange and i worry about hanging a supressor off the end and getting massive poi shift.

Any input
To sum

 

[doverpack12]

My BCA 6 ARC 16” was under $100 and is 30 oz I believe. Could be an ounce lighter.

Shoots very well, I’m moa or better largely depends on me and how good the factory ammo lot is. Haven’t loaded for it yet but plan to soon to really see what it can do.

I have it on a non gas side pull BCA upper, total rifle with SWFA 3-9 is 6 pounds. Shot a coyote at 300 off my pack sitting, shot a long range class with it this spring 450-1000 yards.

 

[ProRoad]

I know there are more lightweight barrels that check these boxes. Any experience on the Faxon, Wilson Combat, etc?

 

[basko152]

I've built two 6.5 grendels on hanson profile barrels that have been quite accurate inside 200.
Last winter I build a 6 arc with a rainier arms match 6arc barrel that is excellent and weighs in around 2.5 lbs. Both setups are full time suppressed. Here is the link to the rainer barrel. Rainier Arms Match barrel.

Edited to add: I've taken several deer with the 6.5 grendel's and have total confidence inside 300 yards. The 6 arc shoots even softer and flatter, so I'll be using that this year for whitetail.

 

[SloppyJ]

Something to consider that I think is integral to a suppressed 6arc build is gas system length. I don't own one but have deeply researched it for the past year and have a plan on putting one together. It seems to be a bit more consistent now. I would shoot for the longest system you can get on that barrel length. It seems if you can get into the rifle length or greater, it provides more wiggle room for tuning. Proof seems to have it figured out with the gas port sizing and the gas system length.

The type of suppressor you're going to run will also dictate the majority of the tuning. I've seen good things from Proof, Craddock, Centurion, and Noveske. I don't know anything about them but Rexus gets a bunch of mentions and they're extremely budget oriented. Whatever I build, I expect the barrel to be the most expensive part 3 or 4 times over.

 

[basko152]

Sloppy is spot on. I ended up installing a rifle speed gas system on mine just to make tuning much more precise and eliminate the spring/buffer experiment. Sure, it’s another 200 bucks but well worth it imho. The rifle cycles like the proverbial sewing machine now.

 

[naked wombats]

Back when I was deep into the grendel AR building wormhole I ultimately ended up using adjustable BCG's to allow for another layer of tuning on a couple rifles. One by 2A armament was infinitely adjustable, and another has 3 or 4 positions.

Not sure if those are still a thing these days, but they do help tune if needed, and dont freeze like some of the adjustable gas blocks do.

 

[ztc92]

I’m no help regarding your specific question but I have found this thread very helpful when considering an accurate, reliable AR build:

K

Thread 'AR = Everything'

Jan 10, 2026

I searched threads and could not find the information I am looking for correct me if this has been covered. I want suggestions on 1-AR setup for all my needs: Barrel length, Suppressor, Optic(s), bullet, and manufacturers. I understand that there is no universal answer for everyone, so included some background which outlines my intended purpose. I am also very familiar with the platform and own a few.

I have lots of guns/gear collected overtime everything from wheel guns to precision rifles. Locations and “needs” have changed, so has firearm/bullet technology and regulation. I am...

• ktm450
• Replies: 166
• Forum: Firearms

 

[cal30_sniper]

16” Proof in 6ARC has worked really well for me. I run it suppressed essentially 100% of the time.

I’ve got a 16” Grendel with the ultralight profile from Odin Works. It also shoots really well, but I’ve been worried about POI shift with a can on it (it’s been a dedicated slick-muzzle rifle its whole life). I’m probably going to try it soon with the new 6.5OG can as it’s light enough to fit the build intent of the rifle.

I’ve had really good luck with the upper end Rainier Arms barrels. Maybe see if they make an Ultramatch in a length and profile that you like. Their fluting is pretty aggressive, resulting in a pretty light barrel most of the time.

 

[SloppyJ]

16” Proof in 6ARC has worked really well for me. I run it suppressed essentially 100% of the time.

I’ve got a 16” Grendel with the ultralight profile from Odin Works. It also shoots really well, but I’ve been worried about POI shift with a can on it (it’s been a dedicated slick-muzzle rifle its whole life). I’m probably going to try it soon with the new 6.5OG can as it’s light enough to fit the build intent of the rifle.

I’ve had really good luck with the upper end Rainier Arms barrels. Maybe see if they make an Ultramatch in a length and profile that you like. Their fluting is pretty aggressive, resulting in a pretty light barrel most of the time.

How are you liking the 16"? Ive been set on a 14.5" but would like to have the rifle length gas system in the 16". What can do you use on it and is it super gassy? The intent of my build is precision first with gas mitigation second.

 

[cal30_sniper]

How are you liking the 16"? Ive been set on a 14.5" but would like to have the rifle length gas system in the 16". What can do you use on it and is it super gassy? The intent of my build is precision first with gas mitigation second.

TBAC Ultra 7 with an SLR adjustable gas block. No issues with gas at all. It’s setup as a lightweight hunting type rig for pigs, yotes, etc.

16” seems perfect. I couldn’t see a reason to step down to 14.5, 16 is plenty short with a can, and like you said, the rifle gas helps with impulse especially when suppressed.

It’s one of my favorite do-all rifles:

 

[RC51kid]

I have to say i forgot i even started this thread so let me up date what i did.

I stuck with 6.5 Grendel. No good reason other than balistics are similar and i had 6.5 ammo. Also i desided to try a budget barrel. If i had dropped coin on a Proof i kight have gone 6 ARC since would hope it would be more accurate and i could push it to longer range.

I desided this would be used for stuff deer/hog/coyote under about 250-300 yards. Mostly as a woods/timber rifle. So 2 moa should be acceptable. I might use it for cow elk in thick timber short range. Except that you know a lot of timber areas you end up on a edge of a clearing and now you have a 300 yard shot. So not sure i will grab this rigle that often if targeting elk.

I ended up with a 16" Rexus. Overall pleased considering how cheap it was. I belive $140 which to menis cheap. Overall its nothing great, but much better than the Faxon "match" Gunner it replaced that vost $100 more.

I have not shot the Rexus enough to really say how it does. But let me compair it a little to the Faxon. The Faxon shot some great .75 groups with Hornady. Then maybe 1.5" groups with most everything else. Then 3" groups with cheap stuff like wolf. I only use wolf for some basic sighting or funtion testing. But then i had days where evn the Hornady would only shoot 2" groups. It was frustrating. It was way over gassed. The brass had huge gouges in the rim and ejected straight forward. Fixed that with a adj gas blovk and buffer. Also had a repeatable but huge 8" poi shift supressed vs unsuppressed. It was frustrating becouse at times it shot very well with multiple sub moa groups with the Hornady.


I desided to try the Rexus and see if it would work "well enough" for my needs before going Craddock or Proof. It does well enough for me. I havent shot it a lot. But i very consistently get between 2- 1 moa with everything i have tried. I belive even wolf shot aboit 2 moa. Some S&B was better still and the the Hornady was about 1.5 to 1.25. But all of those groups had a few holes touching then a flyer. So would say it has potential to be a solid shooter around 1 moa. But the real thing is that it just shoots everything well and is consistent. I would rather have a 1.5 moa gun that is consistent and predictable and thats what it does.

Also it is maybe a little over gassed supressed but so much better. Standard gas block with h2 buffer and supressor throws brass about 2 or 3 olcock, brass looks perfect. I could mess with a adj gas block but it works well supressed and unsuppressed now. Also poi shift is a lot lass but cant remember exactly what it is. Overall i think it will work great for normal ranges i would hunt with. If i was doing a dedicated lr coyote rig i would probably step up to somthing better. But i can ring steel at 340 meters all day and mostly hit the 450 steel once i get my dope. So realistically its a fine inexpensive hunting rig that i will probably use under 200 yards.

I will also say i picked up a Hydrogen K 6.5 to use with it. Part of the reason i dont have perfect data on this barrel is i have been playing with few cans on it rather than just shooting groups. The Hydrogen K 6.5 has been great as a super small light supressor. With the semi action i will still wear ear pro at the range. But i think a shot or two hunting should be no problem. If i remember right it is only about 5" and 6.7oz. On sale was about 750 so kind of a mid priced can. I think it is almost perfect for a short light hunting rifle.

PS. I know 1.5 moa doesnt sound impressive. But i am trying to be honest instead of cherry picking to best group. Realistically think about what accuracy is needed for deer at 100 or 200 yards. I think the shooter and shoot ability of the rifle are much more important.

That all changes if you are making 600 yard shots or shooting small game at 300 yards. Then i do think a sub moa rifle is needed.