Brian T,
There are a lot of good manufacturers of ARs out there. To name a few: Bushmaster, DPMS, Armalite, Olympic, Stag and Rock River Arms. The differences are in pricing and options of what you want on your AR. All of the name brands that I mentioned will give you .5" m.o.a. with the right ammo, offer good reliability and will last a very long time.
I purchased a Rock River Arms A4 Varmint. RRA is used by the F.B.I., U.S. Marshalls, D.E.A. and Force Recon Marines, so if they can rely on them so can I.
Mine has a collapsable stock (green), Hogue combat grip (green), flat top upper, 2-stage National Match trigger, Wilson SS 16" Varmint barrel with a 1:8 twist and a free-float tube. I can get .5" groups at 100 yards with Winchester (white box) ammo 45gr. hollow points. This rifle was $830 out the door! :grin:
If you take an interest in RRA, give Steve a call at Adco Firearms in Sylvania, Ohio and he'll get you what you want at a reasonable price.
www.adcofirearms.com A friend of mine at Camp Lagume just purchased one and plans to use it on his next deployment. He's a USMC Sargent.
Good luck with your choices!
Good hunting, Bowhunter57