Good question I think you want the BFH barrel model it will be more accurate. That is what I am getting.
Don't know how much weight savings the pencil barrel is going to give you, they are harder to shoot off hand. I cannot imagine you would save more than 5-6 ounces but I am guessing.
Barrel from the upper he mentioned:
http://www.bravocompanyusa.com/BCM-...HT-FLUTED-p/bcm-brl-mid-16-elw-f-std.htmApproximate Weight: 1lb 6oz.
Midlength with A2 profile(fat in front/skinny under the forearm)
http://www.bravocompanyusa.com/BCM-16-Mid-Length-Barrel-Stripped-p/bcm-brl-s-mid-16%20std.htmApproximate Weight: 1lb 12oz.
M4A1 profile(mid weight under the forearms with M203 notches
http://www.bravocompanyusa.com/BCM-16-M4-Barrel-Stripped-SOCOM-p/bcm-brl-s-m4%20socom%2016%20std.htmApproximate Weight: 2lbs 1oz.
A full heavy 16" versus the barrel in that upper would be a fairly large drop in weight.
http://www.whiteoakarmament.com/xcart/product.php?productid=17568&cat=312&page=3White Oak Armament 16" .223 Barrel Weight 2.50 lbs