This thread is a bit old, but I'll chime in for people looking for info and posterity:
OP asked about Long Range .223 recomendations. Here's what worked for me in my Rem 700 classic with Nikon 3x9 scope. The rifle is glass bedded and has a Timney trigger. Otherwise it's bone stock.
50 gr Sierra Blitzking
27.3 gr H335
WSR primer
Winchester Case
1.935 inch cartridge base to ogive.
Just about any 50 grainer has worked in this rifle. The load above gets .4 to .6 inch groups at 100. With more work I could probably get it even better, but this has worked for me at the ranges I normally shoot. I've picked off critters at 400 yards. Also took a kid shooting to an F-Class match with this rifle / load combo and he did quite well off a bipod. That's a 600 yard distance. He didn't win of course but he got plenty of X's and 10 ringers. Not bad since he doesn't know how to shoot in the wind.
