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308 AR and carbine vs mid lenght gas system

Hawk45

Gunny Sergeant
Full Member
Minuteman
Mar 29, 2002
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Ohio
Is one going to function better than the other? Would it be best to use an adjustable gas block more on the carbine lenght vs the mid? Thinking about setup on a compact yet balanced 308 AR platform.
 
Re: 308 AR and carbine vs mid lenght gas system

Either will function just fine provided the rifle is assembled correctly. I would suggest the adjustable gas block though. The trick to getting the most out of an AR style rifle is a good trigger, barrel, and properly tuned gas system.
 
Re: 308 AR and carbine vs mid lenght gas system

what barrel length are you going to use? just curious. someone was talking about SBRing a 308 in the box. i wonder what gas he is going to use?
 
Re: 308 AR and carbine vs mid lenght gas system

Thanks guys. I was thinking between 16" - 20" with preference being 16". If I went 18" it would be mid-length and 20" probably rifle length. I really just wanted to make sure the carbine lenght gas system wouldn't beat up the action. No matter what an adjustable gas block seems like a no brainer if the system I decide on doesn't have one.
 
Re: 308 AR and carbine vs mid lenght gas system

My Noveske AR10 18 inch barrel has a carbine length gas system and it runs just fine suppressed and unsuppressed. It does not seem overgassed when running suppressed either.
 
Re: 308 AR and carbine vs mid lenght gas system

After having a mid length system on an AR15 carbine, and then on an AR10 build, I am a convert. Seems to <span style="font-style: italic">me</span> it is smoother and a little easier on the rifle, and on the brass too. And the AR10 uses an old version midlength med wt Chromed bore barrel and has run great suppressed or not.
Most of your "drop in" barrels, especially true with ones made for carbine length gas systems, have a larger port to insure reliability with any trash the consumer throws in it, so you do hear alot about guns, 308's too, being " over gassed" to keep the average joe walmart ammo man from crying about it not cycling. Even KAC had to open up the port some on some of its SR25 Carbines for the consumer market because of complaints from people about it not cycling mil surp type 150 gr range loads.
Top end manufacturers like Noveske tune the port to work as it should for good ammo, so you don't get alot of complaints from those users. Armalite AR10 NM rifles are designed for the 175 and up heavy loads used by LR High power competitors, and are ported as such, and some have an issue cycling mil surp type light loads reliably, and people complain, even though thats not what it was designed to do.
But if it were just a build from stuff i bought, I'd go with a midlength Just because it does feel smoother and easier on the rifle and brass, plus it has worked well for me in my rifles and loads.

SSG Jonathan O'Neal

ETA-- I have no experience with any of the adjustable gas blocks, but haven't felt as I needed them using Mid length or rifle length systems on 5.56 or 7.62 AR's, suppressed or not, but I could see them as a benifit on a carbine system, or if you use a wide variety of ammo with either of the three system lengths to tune to your needs and load. Couldn't hurt, and your brass will probably thank you too.
 
Re: 308 AR and carbine vs mid lenght gas system

I'm pretty sure the Noveske/Armalite designs use a midlength gas system for both 16" and 18" guns. Armalite developed the midlength gas system for the AR-10, and as far as I know, doesn't even offer a carbine length system.

Unless you are building an SBR, I would go with the midlength for sure.
 
Re: 308 AR and carbine vs mid lenght gas system

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jakhamr81</div><div class="ubbcode-body">My Noveske AR10 18 inch barrel has a carbine length gas system and it runs just fine suppressed and unsuppressed. It does not seem overgassed when running suppressed either. </div></div>

I can second this.