For barrels this is a good choice that is $100 less and 3oz lighter:
http://ballisticadvantage.com/16-inch-556-gov-pencil-carbine-cmv-modern-barrel.html
Not target crown, but they would probably do if for you if you call them. If it were 1/9 instead of 1/7 It would be my go to, but you can match your load to the 1/7 so not an issue for hunting.
This one is 6oz lighter
http://faxonfirearms.com/16-pencil-5-56-nato-mid-length-4150-qpq/
You will find that a gov't profile barrel will pretty much always weigh less than the alternative muzzle device, thus 16" of barrel with no muzzle device is lighter than a 14.5" pinned and welded, and it has more muzzle velocity too. So I would think a 16" gov't profile with a target crown is the best possible choice.
IIRC when I tried to do this, using a standard type FSB saves weight and lots of money because you can just get a plain carbon fiber handguard without having to worry about getting one with a rail on it. The tubular ones are much more reasonably priced too. Looks like you're already in the right direction with the A2 buffer tube with a shoulder rest on the end. Is that lighter than the Ace ARUL?
If you're serious about it being in hunting trim when you're done, and want to fight fair, then I'd go with a 4x scope with a single lightweight claw mount ring. Something like the Bushnell Monarch will last you a couple lifetimes, they hunt rhino with that. This will probably help your accuracy because it would also open you up to a floating front end too (no FSB), but the lightest rifle will always be irons so that is probably the way to go if you're serious about winning. One tip I picked up from shooting my AR at 100 yards on irons was to get a KNS precision front sight that is thinner. The standard post covers the whole bullseye at 100yds.
http://www.brownells.com/rifle-part...spx?avs|Manufacturer_1=KNS+PRECISION,+INCxzzx
I personally do not go for the light weight bolts and carriers, to me it's just not worth the headache they seem to come with, and my research as of a couple years ago was that they made the rifle less reliable. You're shooting good quality ammo out of this thing, and I don't think a kaboom is much of a factor. I'd keep the full (or one of the marginally lighter standard) BCG (there is a list on Arfcom by weight), and go polymer lower receiver personally. I spent big bucks on a Mag Tactical magnesium lower when it was new, 5.875 oz, and don't feel like it was worth the money vs a polymer.
For grip, Magpul Kgrip, 2oz.
If you do get a lighter BCG, you've GOT to have an adjustable gas block.
PS: Once you shoot with an A2 length buffer, you won't want to go back to carbine length. It's smoother!
