Quoted:
I going to put a 20"-24" heavy barrel upper on my AR instead of buying another rifle for longer range shooting.  In AR's, I've only had 16" and shorter barrels and never shot them over 50 yds. so the 100 yd plus thing in an AR is new to me.  But, I have shot up to 1,000 yds with other types of rifles.  You can shoot a 16" reliably out to 400 or so yards depending on your setup and skill. And just so you know... a 20-24" heavy barrel is going to be one heavy bitch...

I see RRA and Stag uppers for just under $600.  Is there something better or as good out there for less?  I know in general "you get what you pay for" in firearms but I don't want to invest more that I have to until I see if this is something I'll continue to do. problem with this is that RRA and Stag are really the only ones out there who are doing setups like this anymore... just because of as I said earlier there is little that a 16" can't do that a 24" can... I think 18" is the new happy medium... you could find more options at that length... like a WOA

I  would also appreciate info on exactly what I need to attach a Harris bipod to the rifle.  I assume it attaches to the gas block since the hand guards are free floated but I don't know how.  Do I need a particular type of gas block or attachment or what? It will attach to the freefloat tube... attaching it to the gas block would negate the purpose of the freefloat tube.   you attach a rail to the tube or a swivel...  attach a mount to the rail... then attach the harris to the mount.... or alternatly just attach the harris to the swivel you attached.

And I have read a little about the 6.8 SPC but I have no idea what it would take or whether my 5.56 rifle could be converted to shoot it. check out the variants forum... basically you'll need a new barrel, bolt, and magazines.  

All comments and suggestions are welcome and appreciated.