Question from a newbie

[Chuck 100 yd]

Hi guys , I have built a couple AR15’s but new to the AR’s in .308 . Can I use a barrel with a mid length gas system on my Aero M5

lower with a Carbine buffer and spring? Will it over gas or under gas? Any help would be appreciated.

thanks from the new guy !!!

 

[unforgiven]

I have a 16" and 14.5 M5 with mid gas. I also changed the recoil system to ArmaLite AR10 ... minus stock $60.00. 

I'm also running a .260 Remington on M5 platform. Just my 2 mags

[Chuck 100 yd]

So , are you saying that a mid length gas system will run ok with a carbine recoil system ? Or not ?

this is very confusing to me. 

I see rifle length receiver extensions advertised and rifle springs and buffers but only for fixed stocks. I would like an adjustable length of pull stock. Any suggestions would be appreciated. Thanks. Chuck

[shooterrex]

https://www.armalite.com/product/ar10rekit01-6-position-receiver-extension-kit/

These parts work.

[Armed Eye Doc]

Yes, a properly set up carbine receiver extension and buffer/spring will work with a mid-length gas system.  Both systems depend on each other to tame the recoil, but are independent with regards to setting up each of them.

[Chuck 100 yd]

Thanks guys !!! I want a compact gun , not a long range target rifle. I think I will go with a 16” barrel.

[Armed Eye Doc]

A 16" will still get you out to 500 yds with little trouble. 

Have you bought anything yet?

[392heminut]

The gas system length and the stock system have nothing to do with each other as far as operation. Any gas system length will work with any stock system as long as each is set up properly.

[Cliff R]

"A 16" will still get you out to 500 yds with little trouble"

+2

One of my 308-AR's has a 14.7" barrel and shoots equally as well as the other two I have with 18" barrels.  I'm not seeing any measurable difference it accuracy or bullet drop out to 400 yards.  I suppose at really long ranges the slight loss in velocity would start showing up and require a little more hold-over, but at least within reasonable shooting distances for game (I use these weapons for hunting) I don't even give the barrel length a second thought........Cliff

[jtallen83]

On 7/18/2019 at 3:29 PM, Chuck 100 yd said:

Thanks guys !!! I want a compact gun , not a long range target rifle. I think I will go with a 16” barrel.

About as compact as practical, better jump on one those barrels if you want to build one, been getting PM's on a few different sites asking for details:

 

[Cliff R]

I was looking for compact and weight reduction.  You'd be surprised how much lighter the 14.7" barrel rifle feels in comparison to the 18" versions......Cliff

[98Z5V]

5 hours ago, Cliff R said:

"A 16" will still get you out to 500 yds with little trouble"

+2

One of my 308-AR's has a 14.7" barrel and shoots equally as well as the other two I have with 18" barrels.  I'm not seeing any measurable difference it accuracy or bullet drop out to 400 yards.  I suppose at really long ranges the slight loss in velocity would start showing up and require a little more hold-over, but at least within reasonable shooting distances for game (I use these weapons for hunting) I don't even give the barrel length a second thought........Cliff

Cliff's words are right on the money.  Out to 400 yards, there is very little difference that barrel length will make, on the .308 Win cartridge.  500 is a little different for shorter-over-longer barrels, using the same load.  You start to see the real differences in shorter-over-longer barrels at 600 and beyond.   A month or so ago, I took the 13.5" gun out to 400 yards, with just the red dot, just to make sure I still knew the hold overs. Details of the results are in here: