6.5 Creedmoor in AR

[Buckhammer]

Looking to put an AR-10 together in 6.5 Creedmoor. From what I have "read" on the net I will need to use a high pressure bolt.

Barrel will be 20" so wondering if I should go with a rifle length gas system or go with a +2.

Upper and BCG will be from Eisenach Arms.

What bolt is recommended and what are some other recommended upgrades/parts to make this a reliably functioning rifle?

Any buffer/buffer spring differences?

 

[breastroker]

I have been building sub 6 pound AR308s since 2015. My latest came in at 3.9 pounds complete without scope. Currently building a 6.5 Creedmoor upper using a Xanthos receiver. Hoping to be around 5.5 pounds, my Xanthos lower complete is 15 ounces.

First of all NEVER build an AR308 without an adjustable gas block. Go with standard rifle gas length. Also no flash hider, use a good 2 chamber muzzle brake or a 3 chamber brake. I recommend a JP low drag spiral bolt ring.

For a barrel I recommend Faxon barrels, mine have been their 28.3 ounce 16" 308 barrel that has given me sub MOA using factory ammo @ 110 gr, 132 gr, 168 gr and 175 SMKs.

The barrel length doesn't really matter as much now as an 18 inch 5R will give the same velocity as a 20 inch 6 groove.

 

[JimmyT]

I second the opinion on the adjustable gas block. I would also go with a JP silent captured spring.

I built a 6.5 creedmoor upper for an AR10 lower. Rifle is about 8.5 lbs with out bipod, scope, and ammo. Rifle is a hammer with 18” barrel.

 

[Hobbes442]

keep hearing stories that creedmoor can have problems to feed , could you guys comment ?

 

[bfoosh006]

6.5CM will feed fine from a properly tuned firearm.

FWIW, feeding and function is reliable enough, again from a properly tuned firearm, that I had to stop and think when I last had an issue.

When I say tuned, I use an adj. gb , a heavy buffer and recoil spring... all that is used to slow the cyclic speed from my firearms.

 

[shax2lex]

I know you said you want to build one but there are a lot of stories on the Hide of folks who have struggled to build a 6.5 CM. They ended up spending way more than normal to make it work smoothly. You may want to evaluate just buying one. ARs in 6.5 are harder to build than AR-15s.

 

[KYAggie]

Perhaps I’m an anomaly, but I haven’t had a moments trouble with 6.5 CM AR10 have any sort of problem feeding nor otherwise. And for certain, I’m using parts that few use that are very lightweight, expensive, that you would think might lead to problems. I’m even using a buffer that says in bold writing on the package not to use in AR10’s. I don’t know why others have had such problems with them, but like others have stated, an adjustable gas block is essential to a problem free rifle as well as a good understanding of how the gas system works to cycle the gun so that you can properly tune it. With all the information on the internet these days it’s not hard to figure out how they work. My barrel has a rifle length gas system and I use a JP enhanced bolt with a small firing pin hole made for the 6.5. I would not hesitate to recommend building one. I also trued the face of the receiver before barreling, I’m not sure if that helped alleviate feeding problems or not, but it should help accuracy.


https://www.snipershide.com/shooting/threads/lightweight-2a-arms-xanthos-6-5-cm-build.6877340/

 

[Wile_Coyote]

I've had my 6.5 Creedmoor for a while. Put a lot of rounds through it. Feeding has never been a problem. Same now with my 6mm Creedmoor.

One thing you may want to watch is the bolts. I am running standard on both. Primer cratering was happening on both. The adjustable gas block and silent capture spring tuned it right out of the 6.5 Creedmoor.

The 6mm Creedmoor continues to do it even with an adjustable gas block and SCS with a pierced primer here and there. This was the case with factory ammo. Handloads with WLR primers brought it down somewhat.

For both handloads with a mid table charge produced the best groups and were not far off factory load velocities. The 6.5 I usually go with 147 ELD match, the 6mm likes 108 ELD match or 107 SMK's. Both use H4350.

With those charges, the 6.5 brass isn't beat and I currently have 6 loadings on my current batch of 100. The 6mm started having primer pockets go on the second loading. I just got some brass with SRP pockets but haven't tried it yet. Unfortunately I won't for a while, I just took the Steiner that was on it off as I sold the optic.

With all that being said, the thing you may want to do is run a high pressure bolt. That should cut down any primer issues on firing right away. I may switch the bolt in my 6.5 at some point, but since I'm not seeing issues anymore it won't be anytime soon. The 6mm will be waiting a while as well. Just bought a bolt action to do a custom build with.

My 6.5 Creedmoor AR 10 is my favorite rifle right now hands down. There's nothing I want to change in it. If you build one, I hope you are as pleased as I am.

 

[Cheyenne Bodie]

Brownells has a no furniture Aero 6.5 AR kit for $1049: https://www.brownells.com/firearms/...247.aspx?avs|Cartridge_1=BCC_6xzzx5+Creedmoor

 

[MSTN]

I'd suggest going with +2 gas.

 

[KYAggie]

Wow, that Areo set up from Brownells looks like it weights a ton. Depends on what your application is I suppose. Aero makes decent stuff, just very heavy. If the barrel you want comes in a +2, then great, but I would still use an adjustable gas block. If it doesn’t come in +2, I would not fret over it, again, an adjustable gas block tuned properly, which is not hard to do, takes care of cycling problems in my experience.

 

[Cheyenne Bodie]

Specified by Brownell's at 6.5lbs. You could find one comparatively lighter probably, still seems like a decent bit of kit for ~1K. Swap out the gas block for an adjustable if you want. They have one in 20" also.

 

[Sniper266]

Ive had my 6.5 creedmoor rifle for a while and while i no longer have a need for it in my safe (its for sale) it is a great rifle

I will start with my comment on the feeding issue. My rifle does not feed the 150 SMK’s. The bullet is so long and the ogive is too far back. The nose of the bullet will impact the receiver extension before the feed ramps causing a failure to feed. My rifle does shoot 140 ELDMs very well. I have never tried 142’s.

Adjustable gas block is a must. SLR makes a 15 position block.
I went with a JP LMOS bolt carrier and HP Bolt for lighter recoil.
Also the JP SCS gives you some more adjustability so you can really tune how smooth the rifle is.

 

[stevieb92]

I built a 6.5 CM LR-308 for my Dad in 2015 and then built one for myself in 2016. Both builds were based on the Mega MATEN receiver set. My Dad's rifle used a Krieger custom 22 inch barrel while mine used the BA 22 inch premium barrel. Neither of these rifles I've built ever had a lick of feeding or cycling issues once the gas block setting was dialed in. My Dad shoots factory 140 ELD-M ammo and I handload with the 140 ELD-M. Both rifles are capable of the same accuracy. Yes, both of these rifles are heavy, but they aren't hunting rifles to be carried a lot.

Below is a link to a thread about some load development I did with mine. I had a pretty extensive load development thread on the Scout site but apparently it's gone now. I did cross post my results on the 65creedmoor site so it's available there if you are interested.

https://www.snipershide.com/shootin...vantage-barrel-140-eld-m-h4350-loads.6392411/