Its not a battle comp. Rusty's AR is the lightest AR I've ever held. That thing is pretty sweet.
Also nobody mentions the lower because it has next to nothing to do with the rifle except hold the fire control group and stock, which both of those can be changed to fit the shooter. The actual lower isn't that important as long as its "in spec", which means all the holes line up. Some times you might get an unlucky draw and get an out of spec lower but a call to the manufacturer usually remedies that situation.
Whatever lower you have will work. Changing the stock to better fit your preference for comfort and fit is easy. A good trigger is also very important, unless you're lucky like me and got a sweet stock trigger from the start.
The upper receiver itself isn't important so much either. the only thing there you have to decide on is if you want a forward assist or not. and m4 feed ramps or not. I always want the forward assist. I've seen several, 4 guys actually, not have a round go into battery, no matter how hard they racked the bolt, the round would not seat. Obviously it means something isn't right in the chamber, but it could just mean a little grim is in the way. a hard smack to a forward assist could have saved a stage.
A good barrel is important. length, gas system, twist rate, and material. I went with a 16" mid-length gas, 1:7 twist, stainless steel. its a little heavy, but it works. and works good. It shoots 50 grain JHP's and 55 grain FMJ's very well. I wish it was fluted to save some weight, maybe I'll do that later.
The handguard is personal preference but I would stay away from a quad rail system if you want to be serious about 3 gun and not ATAS. The less weight the better, for the most part.
A bolt carrier group is important. some people can get by with whatever they pickup at a gun show. But i think it takes the most beating and can be the most critical part of the system so I went all out and got the Nickel Boron coated Spike's Tactical M16 BCG. It has more mass than regular and somebody that is sensitive may be able to feel the added reciprocating mass when fired. I can't. Its NEVER miss fired or jammed or double fed or anything. NEVER. It cleans nicely, although I won't be spending the money on a BCG again. I;ll buy a quality BCG from Spike's or BCM, but won't mess with the special coating. Its supposed to be able to run dry forever. That's a lie. All moving parts need oil. Now with oil, it may run longer than a regular BCG with oil. But I don't have the time or funds to test that. Just my theory and opinion.
Optics are preference and I wouldn't skimp on them. A Trijicon TR24 is awesome. A little expensive but not as expensive as most. a 1-4x optic is the way to go, for me. It adds more weight than say an Eothingy or Aimpond. But the ability to switch from a 1 power "red dot" to a 4 power scope is invaluable, to me. The mount is kinda important but if you don't need quick detach capability, than the price can really drop on the mounts. LaRue is still my favorite tho.
This is all my opinion and I am relatively new to this competition thing. I started out with mediocre equipment and upgraded as I went. What I have now I love and I think I shoot decently enough with it. The next step for me is a trigger. And maybe a lightened bolt carrier.
