was thinking of the 16" RRA varmint upper, but I would like a flatop upper with flip up sights, and scope mounted. would prefer 1:7 twist to shoot the heavier longer bullets and I would like some type of rail to mount dual surefire lights on. Anybody gimme an idea of what I can do without spending a ton of dough or getting a shitty upper and putting top of the line accessories on a bbl that doesn't shoot. I am looking for something that will do head shot accuracy at medium ranges---around 300 or 400 yards.---thanks all

Also forgot----I saw a 16" Les Baer upper that had a quad rail that was almost as long as the bbl. Was wondering how difficult this would be---being the RRA has such a large diameter bbl and all.---any help appreciated--thanks

Why not just build what you want?  A good vise, and about $70 for an action block and a good wrench, and you're off to the races.  

One option would be the barrel of your choice, using a YHM customizable tube...it allows you to mount rails at the 3, 6, 9, and 12 positions as you need them.  They have a flip up front sight that mounts to this rail.  

I have 2 of these...one with a ER Shaw barrel, and another with an OLY SUM barrel.  

Or, you could go to a completely railed front end, and a gas block that has the flip up front sight built in.  

When you build your own, you can get *exactly* what you want, and there is more then enough expertise to get you through what is a pretty simple process, once you get past the "oh, shit" stage at the beginning.  

If you  look at the middle rifle in the foreground of this pic, you'll see this tube...it's the "spectre" length, which covers the low profile gas block.  You can see the long rail on the top, and the front sight that mounts to it.  The gas block on the rifle on the right side in the back is the one I was talking about, if you wanted to go that route.  There are LOTS of combos available to get you what you want.  

read up and do lots of looking around here



there is info to cover all your ar needs
and i have never heard of a 5 pos bushmaster stock but hey its your rifle call it what you want