what to build

[jim02]

What say you, new AR build?

Build a 18" rifle in 5.56
or
Build/buy a 18" rifle in 308

Plus for 5.56, cost
Plus for 308, I can use it for deer and elk.

I want something for longer range shooting in a semi auto.

[Irving]

Plus for .308 is that you can shoot subsonic loads with a can on it.
Can use a can for 5.56, but I think you'd have to roll your own for subsonic.

[BPTactical]

308 is the only way to go for distance work. 5.56 will bleed off a bunch of energy in excess of 4-500 yards, plus wind will move a 62 grain slug a bunch more than 168 grains.

[jim02]

I found a nice ar-10a4nm complete upper on armalite site for under $1k, i might buy this tonight and pick up a lower later.
I have not heard of any problems with these uppers, has anyone?
I need a cold shower and better lock up my cc for the night.

[BPTactical]

Armalite is good to go, might be a touch finicky ammo wise. I have only worked with complete rifles in AR10's but I do know that DPMS and Armalites are cut differently at the rear of the upper receiver. I am not sure if you will have fitment issues. Keep that in mind when shopping for a lower.
Worth a little homework.
Barrel length is a consideration. If you are really wanting to see what a 308 can do I would want to stay with a 20" barrel.
There was however a Rock River on the for sale forum that looked decent.

[jim02]

Do all the 308 AR types use a standard ar-15 stock tube and stock?
Armalite, Mega, Dpms.

[jim02]

Do all the 308 AR types use a standard ar-15 stock tube and stock?
Armalite, Mega, Dpms.

Just in case anyone ever reads this and has the same question, I found the answer and so many more about ar-10's on this ar-10 FAQ. http://www.ar15.com/forums/topic.html?b=3&f=62&t=378850