Accurate Upper For Bushie Lower

I've heard good things about Rock River's "accuracy" models:

http://www.rockriverarms.com/item-detail.cfm?ID=AR0500X&storeid=1&image=uva407.gif&CFID=35336013&CFTOKEN=84141066

They have 1 in 8" twist, stainless bull barrels with the Wylde chambering so you can safely shoot either .223 or 5.56. I'm still on the fence about whether to do an M4-style carbine or a looonnng-barreled varmint gun, but these uppers are on my short list.

+2 for RRA.

AR15sales.com

I'm not much for a parts guns or mixing parts from multiple vendors. While they can be lower cost you can have problems with them such as accuracy. I would stick with Bushmaster and get a new upper. You don't need to buy a complete upper you already have the bolt ect...

I ran into a similar problem I wanted a good scoped rifle for varmit hunting. I decided to just put a comb on the stock of my 6551 Colt A2 and mount my scope. Out of pocket was less then $85 to setup I already had the scope and mount. The rifle is awesome for accuracy. I had better then 1/2" groups at 100 yards. One was a oblong hole w/ 7 rnds and three just to the bottom.