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10/12/2016 12:26:45 PM EDT
I'm building a 308 AR. It will have an 18" barrel with mid length gas system. I want to shoot 150 grain or lighter bullets (if that matters). I have not decided on a stock as of yet, but I'm leaning towards a full rifle stock. What buffer/spring do you guys recommend? I'd like to stay away from adjustable gas blocks. This rifle will be shot unsurpressed, for hunting only.

thanks,
swampie
10/12/2016 12:41:21 PM EDT
[#1]
I would still recommend getting an adjustable gas block.
The problem with 308 AR's is that everyone does things a little differently. So, there is no telling how large your gas port will be on the barrel, so there is no telling how heavy of a buffer you may or may not need depending on whatever ammo you choose to use.
Get an SLR Rifleworks adjustable gas block (My personal recommendation I have three of them. There are others out there that work well) and you can pick whatever stock and buffer you want and shoot whatever ammo you want and just turn up or down the gas if you need to. Nothing to do with suppressed use or not, it just makes things work so much better.
From working on several 308 AR's (Both mine and friends) I have come to the impression that there are a lot of overgassed barrels in the 308 market and the proper fix is an adjustable gas block. My friend spent several weeks and a bunch of ammo (both factory and hand loads) trying to get his gun to run well and not jam and pop primers. The final fix was a good adjustable gas block. I tried two different barrels on my 308 and came to the same conclusion. It'll save you a lot of headaches.
Also, if you use an adjustable gas block, you can go lighter on the buffer, reducing reciprocating mass and therefore felt recoil.

Just as an FYI... I went with a VLTOR A5 buffer tube, Armalite spring and a standard AR15 carbine H2 buffer. With the A5's longer buffer tube, you can use AR15 carbine buffers. So, my buffer weight is around 4.6oz. But again, I also run an adjustable gas block (turned down to 3 or 4 clicks from "off" out of 15 total clicks) I have run this system for two years now and haven't had to touch the gas block since I set it up at the first range session.
10/12/2016 1:41:29 PM EDT
[#2]
My 18" middie has a the Slash 6.5 oz buffer, I have the sopmod stock on mine.



I do have an adjustable block, but the buffer worked fine with a non adjustable before I switched.
10/13/2016 11:28:54 PM EDT
[#3]
Quote History
Quoted:
My 18" middie has a the Slash 6.5 oz buffer, I have the sopmod stock on mine.

I do have an adjustable block, but the buffer worked fine with a non adjustable before I switched.
View Quote



This is what I was hoping to see. I shall try this method first. Are you using a special spring?

swampie
10/14/2016 2:23:41 AM EDT
[#4]
Depends on your gas port diameter and the location of vent holes on the BCG, quality of the gas rings and critical dimensions of the bolt and carrier, chamber design, rifling depth, etc.

Be prepared to use something different if your first choice doesn't work.
10/14/2016 12:30:00 PM EDT
[#5]
Once I get this project completed, how will I know if everything is timed just right? Of course I know it needs to reliably feed and eject but how will I know if I need an adjustable gas block?
10/15/2016 8:41:17 AM EDT
[#6]
I use a slashe's 10 oz. XH  rifle buffer in my Bushmaster 7.62 MOE and a CAR 10 5.5 oz. in my DPMS G2 MOE. Each firearm has at least 4000 rounds through it and run fine.
10/15/2016 9:09:11 AM EDT
[#7]
I would try to find a 1/12 twist barrel if that's your intention. None of my 1/10 308's shoot worth a damn with 150's.

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