308 16" L/W rifle length gas build

I have been wanting to shoot a 16" .308 with a rifle length gas system since seeing Buckjay's 16" LMT build. I had a CMMG 18" mid length complete that I got for $1100 in early 2012. I sold the 18" barrel and ordered a Fulton Armory 16" L/W with rifle length gas system. I went this afternoon shot it on paper at 25yds then to 100yds.
http://fototime.com/7B7078259CC5ACA/standard.jpg

First 2 shots low turned the Leupold 1.5x5 up 1" and fired 8 more shots. Its shoots better than I expected for a lightweight barrel and it so soft to shoot compared to my other mid-length 308's.
http://fototime.com/638C109DEA1CAA9/standard.jpg

ETA:Build info 12" Troy TRX with Noveske bipod stud ,Noveske quick detach socket, JP trigger, JP low mass BCG 5 oz lighter than a standard BCG,Vltor A5 RE with H3 buffer, Mapul STR and Magpul Moe +. 16" Light Weight Fulton Armory barrel has .625 gas block seat BCM gas block. ETA: scope is the Leupold 1.5x5 CMR-2 reticle.

Thats a slick looking piece. I also have a 308 AR in process that getting a Fulton Armory barrel (sourced from Criterion I believe). It is getting one of their 20" heavy contour barrels. Lower/upper is SI Defense, rail is a TRX-308 just like yours.

I think that the 16" rifle gas is a fantastic combo for a 308 AR. About as light and fast-handling as you can get for a 308 Win semi auto rifle...

I also imagine that it will shoot better with a couple more rounds down the pipe.

Nice build & smokepole.

enjoy !

Nice rifle OP!

Nice looking rig OP. How many rounds have you fired through it and have you had any failures?

twisted: I have fired only 14 rounds so far.

I'm very interested in this project.

Please update this with accuracy and reliability info as much as possible.

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Originally Posted by archad

twisted: I have fired only 14 rounds so far.

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I feel your pain. I got my Sig 716 in early December. I have just recently shot it past the 150 mark.

Also very interested in reliability potential of rifle length gas in barrels <20".

Same deal with intermediate length gas on a 16 5.56. Or mid-length gas on a 13.5, or rifle-length on an 18.

As long as it's a *competently* factory produced barrel (not something somebody chopped off 4 inches off the end and called it good) with a properly engineered gas port, then it should be reliable.
Cheap milsurp 7.62 would be the test ammo ran with a dirty, gummed up bolt/carrier in all temp ranges.

Quote:

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Originally Posted by carbinero

Also very interested in reliability potential of rifle length gas in barrels <20".

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Same here. I currently have an Armalite AR10 w/ 20" barrel, and while I do like the setup, a more compact package would be nice. Looking how little barrel there is after the gas block does have me curious as to reliability as well.

http://img.photobucket.com/albums/v1...leRifle-33.jpg

Rifle length gas and 16" 7.62mm barrel -- its be done ;)



Edit - note AR10 has a longer than rifle length gas system -- would not chop less than 17.25" unless your planning dedicated can setup

1) Different bullet weights and different powder burn rates make for different gas port pressure and time under pressure. The longer the gas systems and shorter the barrel after the gas port the more effect it has on cycling. I find the 7.62 AR to be more sensitive to this than the AR-15.

2) It's important to realize that at some point "soft shooting" becomes "likely to choke" if it gets dirty or is underlubed.

I'm not claiming this is going to be unreliable, but I would put a lot of rounds (the same ones that will be used for defense) through it before making it a defensive weapon.

Sorry for the resurrection guys but I'm checking around on the 16" w/rifle length gas system combo before I start having my 20" AR-10T bbl chopped.

archdad,

Do you know what your port size is?


KevinB,

Have you seen anyone remedy the <17.25" Armalite issue by opening the gas port?

Thanks Guys,
Keith