Would like to put either a 20'' E3 or 24'' from M & A Parts on a rockriver lower. Anyone have any expierence with a 24'' at 200 plus yards. Does the extra 4'' make a difference in accuracy .

Are you planning on getting a bull bbl 20 or 24 or just an Hbar? It is my understanding that accuracyt isn't so much the question but more the velocity...your bullets will still have a bit more head of steam at the greater ranges with the longer bbl. You can have a shorter bbl say 16" and still have great accuracy....you just won't have the power behind the bullet. On the other hand a 24" HABR with bayo lug and f/s....to me....looks silly....a little disportionate. I hope I spelled that right...we used to have a spell check here....grrr

Just put a 24" M&A Hbar upper on.  Took it to the range to sight it in at 150 meters.  Cannot verify any more accurate, as do not have a scope on it yet.   The heft is better to me, is a little disproportionate as Colt_sporter says until you get used to it.  One thing for sure, it is quieter than my 20" upper and a bit less recoil.  Hope this helps

Barrels don't get any more accurate as they get longer.  A lot of long range AR's wear barrels from 16-18 inches.  Longer barrels add a LITTLE more velocity.

If your longer barrel is smaller than your shorter one, IT will be less accurate.

Just found an upper from model 1 sales, standard hvy barrel (not bull,) 24'' A3 with alumium free float hand guard,gas block sight base.1:9 twist for $400.  the bull brl varmit run $480. The price for the same 24''A3 from M&A is the same. IM leaning towards the 24E3 satndard brl.Already have a 16'' dpms dissipator from CMMG on the way so I want to reach out and touch some one but I dont want the weight of the bull barrel.

I'd get a 16 inch bull barrel

Seth

What are you going to be shooting with this bbl?

We 'll be shooting paper targets at 100,200,and 300 yards .Hopefully various varmit hunting,coyote ,wood chuck....