18" AR-10 barrels. Carbine or Rifle length gas??

[demonsmokr]

Im an AR noob. I know AR-15s have carbine, mid, and rifle length gas systems. I was curious about AR-10s. I have seen only carbine and rifle length. I want an 18" barrel, and the only company I have found that makes finished 18" barrels for Armalites is Noveske. I emailed them and they said they use a carbine length system, which is 1/4 inch longer than AR-15 mid length. Is there a reason for using a carbine length gas system on an 18" barrel? Is there any pros or cons to either one? Or did Noveske just use carbine gas to make it easier for mass production? I asked my local smith, and he says there would be no noticeable difference if I have my 20" cut down to 18". Thank you for any education

 

[AXEMAN]

Re: 18" AR-10 barrels. Carbine or Rifle length gas??

i have been doing this dance for some time. you may be able to use a krieger from fulton. i called and they say they use rifle in the 16" and 18" lengths that they offer. knights has a 16" with rifle, the post that introduced it here said they did alot of work in getting it reliable. dpms only uses rifle for 20"-24" and carbine for 16"-18" that i have been able to tell from their press and catalog. i found a place that offers polygonal rifling and 18" in a mid gas.

my concern is after reading the post on the knights .308 carbine is that they refer to many hours of high speed filming and changing the gas system some. and what my chances of getting a 16" with rifle gas to function. open the port all the way and start with an adjustable gas block? i can see a 18" with rifle gas, but 16" im not sure about. you dont have too many choices in what configurations you can get. i dont know is there is a formula for what works in 308 loike there is in the ar15 platform

 

[demonsmokr]

Re: 18" AR-10 barrels. Carbine or Rifle length gas??

I talked to another gun smith today. He gave me some decent advice. He basically said just leave it alone, the .308 was designed to be fired from a 20" to 21" barrel from the start. I can understand what he means. My only real reason for cutting down to 18" was aesthetics anyways. I am getting a 15" free float rail and it looks real nice on an 18" barrel. I think I going to stick with what I have, and not dick around with the barrel. If anything, I need to get my hands on an Armalite SASS barrel. They wont say who they have make them either, all I know its one bad ass barrel. They use criterion I believe for the mass prod. barrels. I have seen CMMG's uppers with 16" rifle length gas. I dont know how well that would work, on either platform. I think they need to find someway to make a midlength gas sytem just for 18" barrels. Im sure it would work the best, the only thing is you would need a new gas tube. Thats all I could think of, but Im no smith.

 

[AXEMAN]

Re: 18" AR-10 barrels. Carbine or Rifle length gas??

you can get mid gas, all you gotta do is find a maker that will do it for you or that offers it. if you get a blank, you can get the mid gas. 18" is doable. thats what i have in mind, with mid gas. plenty here have gotten out pretty far and accurate with 18" and even 16" in 308. soomeone just build a 16" 308 with mid, its in the "black rifle builds complete" thread by big joe i think. nice 16" mid carbine. build it how you want man. thats what im doing. people get 16" with rifle gas to work somehow too. im just buying the barrel last, hoping ill get something figured out by the time i have to get the barrel. its BCG next, then barrel