18" barrel mid-length vs rifle length gas system

[zinny]

hi guys,

i will be ordering a new ar-15 soon. i would like the rifle to have an 18 inch barrel. my question is should i get a rifle length or midlength gas system for it. the primary reason for my debate is of ascetics vs function. i've read that the rifle should shoot softer with a rifle length system, but i would like to be able to hide the gas block under the rail as i feel that its more ascetically appealing. furthermore, ive read somewhere that with lighter loads, an 18" barrel with a rifle length system is prone to cycling issues, is this true? so i guess my real question is of those who have shoot 18" barreled rifle with both kinds of systems, how much "harder" does an 18" barrel with a mid-length system shoot?

p.s. oh and are there any other pros vs. cons that should be considered?

 

[jakhamr81]

Re: 18" barrel mid-length vs rifle length gsa system

I have an 18 inch with a mid length under a Troy MRF 13 inch rail. hold .9 inch groups at a hundred with Black Hills 77 grain, and the recoil is hardly noticeable. It functions and cycles great. I don't see a reason to go to a rifle length system.

 

[tt350z]

Re: 18" barrel mid-length vs rifle length gsa system

I use a 18'' with rifle gas. I have no issues with it cycling 50g JHP from walmart. Even in the cold cold winter in north dakota

I built my AR to be as soft shooting as possible since I plan on shooting multi-guns with it. It's been awhile since I've shot a 18'' middy, so I can't really compare.

Aesthetically, it doesn't bother me that the gas block is exposed. But if looks matters THAT much to you to consider against a rifle gas... well that's your decision. Of course you could always buy a 13'' rail and cover up the rifle length gas.

 

[zinny]

Re: 18" barrel mid-length vs rifle length gsa system

well im sure im going to get a compasslake varmint rifle. 99% of gas blocks look nice to me, the low-pro block they have on their space/varmint rifles looks funky to me. which is why i want to see it there's a good amount of difference in how the two systems shoot. if there isn't ill go with the mid length. if there is, ill go with the rifle length.

 

[tt350z]

Re: 18" barrel mid-length vs rifle length gsa system

Is this the gas block you're talking about?

If so, I'm not a fan of that style either. You shouldn't need that version unless you are changing the front sight base on a barrel that isn't parkerized underneath, this longer gas block will cover up the unparkerized/scratched up area. Or you just like the looks of it.

Like anything, you can swap it out with a gas block you like afterwords. Just a roll pin and 2 set screws and voila, the gas block is off.

 

[zinny]

Re: 18" barrel mid-length vs rifle length gsa system

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: tt350z</div><div class="ubbcode-body">Is this the gas block you're talking about?

Like anything, you can swap it out with a gas block you like afterwords. Just a roll pin and 2 set screws and voila, the gas block is off. </div></div>

yes thats the one im talking about. the problem is their barrels for the space/ varmint is .850 in diameter, the low-pro .750 dia gas blocks are too small and .875 ones are too big for the barrel, so im basically stuck with it. therefore my two options are to either let it be or hide it, should be obvious which i would prefer more.

 

[KevinB-KAC]

Re: 18" barrel mid-length vs rifle length gsa system

Really you want the longest gas system that will cycle your gun without a abnormally large gas port.

18" with rifle gas is the way to go.

 

[rasp65]

Re: 18" barrel mid-length vs rifle length gas system

Zinn My 18"6.5 Grendel has a mid-length gas system. I used a JP low profile adjustable gas block and it fits under their rifle length handguard nicely. The adjustable gas block will take care of any potential overgassing problems.

 

[shooting4life]

Re: 18" barrel mid-length vs rifle length gas system

Here is my jp with 18 inch barrel and rifle gas length. I think it's sexy. Between the comp, adjustable gas block, low mass carrier and buffer I have the thing shooting like a 10/22 with no movement. Those 3 gun guys sure know whatthey are doing when coming with new ways to build an ar.