Check out the Vortex Crossfire II 6-18x44, it is available with a BDC for around $220. You could also look at the Redfield Revenge 6-18x44 with the Accu-Range reticle, they run about $250. Nikon Buckmasters run a little out of your price range but if your willing to got up $20 you could check out the 4.5-14x40 Buckmaster for $320. All of these scopes are very nice and I have personal experience with the Redfield 6-18 on my cousins .243 and a Buckmaster on my Dad's M1A. I can vouch for the Redfield and Nikon's clarity and their positive clicks. I recommended the Vortex because of their outstanding warranty and the great reviews I've read on them. Hope this helps!