Hello, I need Your opinions on AR 308 barrel/gas system length!

Barrel will be made from stainless  Bartlein blank. Original plan was to make a 16" heavy profile barrel with .875 GB (adjustable) and mid-length gas system.
Now I'm leaning towards 18" barrel length for better compatibility with different .308 ammunition types/weights...
And after finding this archived thread http://www.ar15.com/archive/topic.html?b=3&f=121&t=486201
I'm starting to think that 18" barrel with rifle gas system will work better/more reliably than 16"/mid in 308...

Any thoughts/opinions/real life experience that can help me to make a final choice will be greatly appreciated :)

Thanks!

Depends what range you wanna shoot at. I have both16" and 20" RLGS. Both are super smooth in terms of recoil for the .308, both running heavy buffers and SLR adjustable gas too though. Both shoot fantastically, but haven't taken them past 500m yet. I suspect when I make it to a range 800m and beyond, the 20" will shine. I think the 18" Is just a compromise. If you want 1k ability get a 20" or greater. If you want a 600m blaster, get a 16". RLGS is what these guns need though so get it either way.

Well since you are in the Ukraine, If I was shooting at Russians I would want the 16 with a rifle lengthfor mobility purposes.

I'd go rifle length gas with either 16" or 18".

Rifle length gas on a 16"?  Wouldn't even take my chances in that, no matter how great Fulton Armory says it can work lol

Knights has been building 308 ARs longer than anyone and they use a rifle length gas system on their 16" carbine.  There are other 308 AR rifle manufacturers selling 16" barreled rifles with rifle length gas systems as well.  There are several folks here who have cut 20" 308 AR barrels down to 16" and still cut the gas back with adjustable gas blocks.  I believe Fulton Armory was one of the first to realize that a short gas system is unecessary because they started out working with M1A/M14s.  Look at the gas port location on a Springfield SOCOM some time.

Rifle length with either length,  I have an 18 inches with an .875 diameter at the GB. Shooting out to 1k yards on 1.2 moa plate was a piece o cake. I prefer to have the extra 2 inches even though I know 16 inchers are effective but 18 is as short as I would go on a precision/ DMR type rifle. Running and gunning is a different story.

I'd go with 18 inches on a 7.62.  If you are going carbine length on the .308, it seems to be the most ideal in performance from my experience.  I prefer a RIFLE length barrel such as a 20 or 22 inch BUT you do sacrifice a bit of mobility.





You can still get very good reliability with a rifle length gas system on .308...and if you are building an AR308 platform, do go with a good, adjustable gas block if you can get one.





Most of my carbine rifle experience in .308 is with the M14 style weapons, so I am a bit biased as I found the 16 inch M14 style guns to be a bit too finicky.





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The pics are just for fun.....



 

As long as I've been building m14s/m1a's and fals typically you never go under 18", sbr fals are a different story but you'll need azex to chime in on that, under 16 you're asking for trouble no matter what a manufacturer says.

I have a few .308s with barrels less than 16", they all shoot like a dream.  To be honest I would never build or buy anything in .308 with a barrel longer than 16" unless it was a period piece, ie HK91, FAL, etc.

If you have the proper gas port size, you will have ZERO problems with a rifle gas 16" .308. I love mine, and would never think of going with a longer barrel ever again in a .308.

Rifle gas is the right gas on the 16 inch .308/7.62 NATO.

First of all thanks for Your help!

My initial plan was to get 16" barrel for mobility (especially with a can that will be rather large/heavy for 308)!
But the local manufacturer of 223/308 AR's is now testing different barrel lengths/profiles and their test shows that 16" barrels can be sensitive to ammunition. We have very limited availability of .308 ammunition right now so this can be a problems and 18"  barrel looks like a better choice.

The second problem is that I was wrong assuming to use mid-length gas  system on 16" barrel and already have purchased a 13" FF hand-guard... I looks like 13" hand-guard will not fully cover GB on a rifle length gas system... :(

I've already have a heaviest buffer from HeavyBuffers and a rifle receiver extension. Because the cost of the 308 AR will be very high (2x higher than in US) it's better to choose all components thoroughly :)

If reliability is your main concern I would probably buy a factory built gun, upper, or barrel rather than trying to configure my own. I had a Armalite AR10 carbine and it's mid length gas system ate everything I fed it including surplus and wolf.