I built up what has become my favorite .308...but it doesn't shoot accurately. The intended use is the "if I could only have one rifle" build. I wanted something light enough to carry and hunt with out west all day while being accurate enough to kill a deer at 500 yards. I put a Faxon 18in pencil on there figuring it would be accurate enough and light enough, and that's not the case. It will barely hold 2.5 MOA and is pretty random with fliers.

I'm thinking 18in Criterion and just accepting the extra half pound of weight. Is there anything else I should be considering?

2.5 moa with what ammo? Criterion is awesome though and will be a better barrel. However, if you are shooting crap ammo, don't expect just the barrel to significantly reduce group size.

Federal Gold Medal Match, Black Hills, handloads run through a concentricity gauge...it's all 2.5 MOA at best. The BH load shoots .5 MOA consistently through an M40 build I have, so I know it isn't me and it isn't the ammo. It's the barrel.

I’ve heard that the Faxon AR10 barrels are really hit or miss.

18" pencil is probably not the best starting point if precision is the goal, especially with a .308.
Can be done but tuning out barrel whip can be a booger, especially if there is any shooter inconsistency.
Autos tend to be more sensitive to technique than a heavy barreled bolt gun.

I'd lean towards a light taper.
What optic?

Take it from someone that just did this in the 16" flavor get a Criterion and be done with it.  I got a hybrid and is super accurate. Pretty impressive with M80 ball even

Definitely sounds like it! I've had a .223 Wylde Core and currently have a 8.5" Core in 300 blk. I'd go Criterion.

My faxon 308 barrel was ringing gongs at 500

i decided to upgrade it to a fluted Aero from schuyler  , I need to get that set up sighted back in

Athlon 1-10.

I'm not looking for precision, but 2.5 MOA is pretty awful. I know it is the barrel. I have a Savage MSR Hunter 16in that is a consistent 1.5 MOA shooter with anything, and with handloads is an honest 5 shot 1 MOA rifle. It isn't me, it isn't technique, it isn't ammo. This rifle just will not shoot less than 2.5 MOA under any circumstances. I'm just looking to know what barrel to replace it with as Faxon has lost my interest.

CRITERION

I'm happy with my Rainier Arms Ultramatch.

I've had two Faxon .308 barrels.  Neither shot all that well.  First was exchanged by Faxon.  Replacement wasn't much better so I sold it.

I have a Criterion now that is a solid 1 MOA shooter with good ammo.

WOW.

What Criterion did you go with? Best place to buy?

I'm leaning towards this one.
https://criterionbarrels.com/products/large-frame-ar/m118lr-308-win-7-62x51-nato/dpms-pattern-308-hybrid-barrel-rifle-gas-chrome/?v=7516fd43adaa

Got it direct from Criterion.  I bought the 20" with nitride finish, mostly because it was in stock and ready to ship.  No complaints.

I like the one you're considering too.

I have a Faxon Big Gunner 18” 308 that shoots 2 moa from my AR10 build and I’m definitely the cause of at least .5 moa of that.

I started with Criterion, my first .308. The next two have Noveske
barrels.

My favorite is the Criterion. It's is just as good as I am
hitting the mark. All three of my .308's are 16" rifle gas as well.

This site is GTG: https://ar15discounts.com/products/criterion-barrels-18-308-m118-hybrid-nitride-midlength-barrel/

Stainless available: https://modernwarriors.com/product/criterion-barrels-m118-dpms-hybrid-.308-win-18-rifle-gas-stainless-steel

Have you contacted Faxon to see what they say?

Both my Faxon barrels are .55 or .65" shooters.

Nope. I don't know what they would say, but I don't really care. The barrel functions fine, and does what a barrel does. It just doesn't do it well. As to Faxon barrels being  a .5 MOA shooter, if you can string 5 five shot groups together and post pictures where we can't see the powder burns, I'll believe it.

But I still won't believe it.

Just like other commercial brands they do put out a shooter every now and then.
I've had MOA or better barrels from DPMS, Faxon, Ballistic Advantage.
It's not guaranteed but it does happen.

I am really pleased with the Criterion barrel I have.  I did a 20" hybrid rifle gas nitride barrel and although I am not an expert shooters so far it is more than capable of putting up tight groups.  It would probably do better with a better shooter behind it.  Even with quality ammo not match but not cheap ammo it will put up 1.5" groups and match ammo around 1".  
I am happy with the outcome of the rifle overall and as I try more and more different loads I think I will lock down the best load it likes.

Criterion mid weight match, 20" from Fulton Armory. Shooting Nosler Factory "seconds" 168 over IMR 4064. 200yds targets and 500yds

Dunno if you are into accurizing your rifle, but.

With a Criterion 18.5" barrel from Fulton, I was frustrated with fliers after the first shots would land touching.

After reading, faced off the receiver to true the surface, and shimmed the barrel to receiver with .001" stainless shim.  
Had to thermo fit it.  

Pretty much stopped the fliers even with junk white box M80 ammo.

I have a Proof Research 308 barrel that shoots 1/2” Moa
Love it. And that’s just factory loads. 1  11/16” at 200 yard's.;

I guess it depends on the rifle you have, but being light enough to carry all day, and accurate enough for deer at 500 yards at the same time is asking quite a bit of a semi auto 308 of any kind. I would be putting all I could into the barrel, and I'd be looking at a good cut rifled barrel, not that I think Criterion is bad. If any offer fluted barrels, that can save some weight.

When I think of "walk all day" rifle, I'm thinking under 10 pounds, and under 9 would be better. I just don't see an AR10 under 10 pounds having the capability of a 500 yard shot. Just the scope needed for such shooting pushes it up. People have a hard enough time getting a combo like that with a bolt action like a Tikka T3 lite.

Or you could just accept some limitation, say 300 yards. Then you can get away with much less. 1.5 MOA accuracy is fine, and standard rifle scopes work good enough.

Won't say anything about Criterion other than when you get a good one its pretty good.

I would go with Craddock all day long though.  All...day.  Get a RTR barrel if its in stock the way you like it.  

This is about where I’m at. I’ve had a few criterions. I’ve had generally favorable opinions of them, and so regard the brand highly, mostly for the price to value. For the price, you’re getting a lot of barrel. But at the same time mine have been varying in overall precision, and have often been pretty ammo picky. Doesn’t seem to be a lot of rhyme or reason either. Every barrel has been a crapshoot in terms of what it likes, and what it hates. It gets to where I’ll try one out and if it doesn’t shoot what I want it to shoot, I’ll sell it off and try again.

I do have two RTRs coming in, and one signature series. Craddock has an excellent rep and I’ve used them before. I have full confidence they’ll be great barrels, and the same confidence that in the off chance they’re not that Craddock will take good care of me. They’re a pretty cool company in my limited dealings with them.

Pencil barrels would not be my choice for a 500 yard deer rifle. One shot accuracy might be there, but pencils heat up and have a better chance a bad harmonics.

The Criterion I had was MOA, but it was a heavy profile. Not really apples to apples. The Faxon barrels i had were just gov or m4. All within spec.

I have two Medium contour (now I think they call it the Big Gunner).

One is awesome and the other sucks.

I am an FFL and an armorer. I have built several dozen of large frame ARs last couple of years. I have noticed a few things they have in common.

1) they are just not as inherently accurate as their 5.56 brethren. Most are about 2-3 MOA on a good day. Just how it is.

2) The barrel makes a massive difference. Even a lot of cheap nitride barrels on 5.56 can crank out 1.5 MOA or better. A quality barrel makes a huge difference. The .308 barrels I am confident are accurate are: Rainier, Criterion, and Wilson Combat. All are about the same in accuracy. I am very impressed with the Wilson Combat when they have their 25% off sale. I like Faxon, but am underwhelmed with their .308 barrels, ballistic Advantage too.

3) Ammo, in regards to run of mill M80 ball ammo in not as consistent as 193 or stand 5.56 ammo. Most AR .308s with a 1-10 or similar like 168 SMK. I use it as a baseline to compare to most of the time.

4) the receiver/barrel nut interface is critical. The receiver is bigger, the barrel is bigger, and the pressures are higher. A quality steel barrel nut is a variable that should be addressed. Because the rail selection is more limited in large frame ARs, I can confidently endorse the MI barrel nut, SOLGW, and SLR. There are probably lots of other good systems that aid in accuracy, but I use those 3 more than anything else.

5) I can’t prove it, but I am a believer some BCG can aid in accuracy. I use Aero and stick with them.


I built this and it is sub MOA. Has a Wilson Combat 16” barrel and MI rail. Once I zeroed it and saw it was sub MOA, I am not changing a thing. I don’t want to upset the .308 AR Gods and cause unintended consequences. I was going to put a Reptilia scope mount on it, nope, not changing a thing.
It is surprisingly accurate with M80 ball. Can hit any steel target any practical distance. With 168 SMK, all the rounds touch on paper.

Attached File

I built my Aero M5 around the Criterion 18" M118 LR barrel and have never regretted it.

It shoots better than I can.

https://criterionbarrels.com/products/large-frame-ar/m118lr-308-win-7-62x51-nato/dpms-pattern-308-hybrid-barrel-rifle-gas-nitride/?v=7516fd43adaa

I use the standard M5 buffer and spring with a non adjustable gas block, and have never needed an adjustable block...it just runs. Attached File

criterion is great.

i typically run rainier arms barrels. they shoot dead nuts accurate. not that expensive and you can get varying profiles and lengths.

I’ve tried to like Faxons but they keep disappointing me. I’ve been pretty happy with BA for cheapie barrels

Noveske or Criterion

I had a faxon. Would not shoot no matter what ammo I fed it. Changed to a Rainer select. Better, but still not impressive. Then switched to a Criterion. Very happy with it. I have two other AR10’s both equipped with 20 inch Kriegers. They are absolutely the best(shot .346 last weekend). For the money the Criterion is a great deal.

I bought a criterion 18" 308 barrel some years back and a couple thousand rounds of bulk M118LR expecting magic to happen.

Can't print less than 2MOA with it and i was pissed.

Then i shot some 147 grain PPU for shits and giggles and had sub-MOA results. Guess the rumors about the bulk M118LR were true.

It renewed my faith in the criterion barrel, and shat upon my faith in the M118.

Another funny thing is that with an LVPO on my G3k SBR clone, it also shot MOA with the PPU. I was impressed.

This…..and if I remember correctly they use Bartlein

Bartlein

Rainier match barrels shoot fantastic

I have tried a couple different barrels in our R2000. This is the result of just doing function testing with a new Criterion Core barrel 16". This was at only 15 yards but I was not set up for accuracy testing, just function testing that day with General Dynamics ammo. Every barrel from Criterion I have tested has been the same. I am a average good shot but not great by any means. I have only had accuracy like this from one other rifle which is a Weatherby 375. I really like Criterion.

I find this exceedingly difficult to believe.

I have a 16 criterion hybrid match barrel it shoots at best 1moa and that only happens when I do my part . I also have a 16 faxon pencil 308 barrel and with the best ammo I have it’s a 2to3 moa rifle . Some members hear like to exaggerate there abilities when comes down to accuracy .

Just an update on this. We have some Criterion Hbar chrome lined barrels coming in next week. I will try to test them with some Hornady match ammo at distance and see if I can hold the accuracy I get in the 15 yard test range I use. These are in .223, the 308 testing is still off a couple months.

I normally like the Criterion Core barrels but they only had Hbar so we went with those. I will test in 16" and 20"

All the good scopes are out on loan, so that will be the weak link...besides me.

I could never get my Faxons much under 1.5”

I have a Faxon Gunner in 6.5 Grendel that shoots very well. Defiantly sub MOA. But, it is a little ammo sensitive. Did not like Wolf crap and opened up to about 2.5 MOA. PPU 110gr was also about 2 MOA. With Hornady Black, A Max or other good ammo it was about MOA. Something about the platform made it a little more work for me to get really good results. But when i did my part right it was MOA. The thin contour did give more POI shift than i liked with heavy suppressors but it was 100% repeatable. Yes this particular picture is only a 3 shot group. I admit that it doesn't really count since it isnt 5 shots. But I would still say the rifle shoots MOA or close with ammo it like. It is capable of it but it takes some work.



Next build i wanted slightly heavier to have less POI shift with suppressor but still light rifle to carry all day. Went with a Rainer light weight match 16" in 5.56 wylde chamber. I know it is not the caliber you asked about. The Rainer match barrels are not as good as the Ultra match. But this rifle shoots cheap AAC 75gr and  77gr. very well.  I just haven't put a lot of time into shooting this one because it just kind of worked so well right from the start.
Found this picture, yes its only 4 shots not five. I think it was my first range trip with the Rainer barrel trying to get it sighted and playing with different ammo. You can see i was just shooting paper plates.

Recently i got a used Criterion CORE. Yes it is used with a unknown round count. I have only fired about 10 rounds through it just to check function and groups were acceptable. But not as good as the Rainer. I will give it another try for sure. Criterion has a great reputation, and it was beautifully gassed. dropping all the casings in a nice little pile. I have hopes that the Criterion will replace my Rainer. But at this point the Rainer shoots better than my particular Criterion.

I know these are not .308. But it is some of the brands you are talking about. I am a very average shooter, not a experienced longrange shooter. If i am just shooting for fun and playing with ammo or adjusting sight I often only shoot 3 or 4 shot groups. If i have 3 or 4 rounds down range and people want a cold range I will stop. OrI might be finishing up one box of ammo and only have 4 rounds left with me. If I am working with something more important like a rifle for hunting I will do multiple 5 shot groups. Just saying dont get bent that these arnt 5 shot groups.

This is impressive. Makes want to take down what i just posted. But i never have the patience to shoot 10 shot groups. Someday i will, I know it is the right way to do things.

It's okay to shoot smaller size samples, but back it up with more samples. Three 10 shot groups or ten 3 shot groups. The composite should be similar.

I like doing three or four five-shot groups to get a good feel for it. Is that better or worse than one ten-shot group? There’s a statistically valid answer to that question that I don’t care to find, but it’s what I do. Either are far more meaningful than single 3-shot groups though.