If I were looking for a serious long range rifle, and weight wasn't an issue, I'd probably start with a Remington M700 Sendero. I'd have a 26" Kreiger barrel installed in the same contour as the stock Sendero and chambered in 7mm STW. I'd also install a Timney or Rifle Basix hunting trigger, blueprint and bed the action and top it with a nice Nikon Monarch or maybe even a Zeiss Conquest scope with a top magnification of 14-16x. Then you're going to want to get yourself a handloading setup and work up some loads with a high BC 160gr bullet like the Accubond, Ballistic Tip, or Interbond. Then spend a lot of time on the range fine tuning the rifle and load for max accuracy, then more time learning the trajectory of the rifle. If you don't have a rangefinder, then you'd be well advised to practice range estimation until you have it down to within +/- 25 yards out to at least 600 yards. Even if you do have a rangefinder, practicing range estimation and practicing on an unknown distance course is a good idea. You'd better also learn how to dope the wind really well by reading mirage, observing the motion of grass and trees, etc... because any bullet will drift far enough to completely miss a deer even in a 10mph full value crosswind at 500+ yards. Be prepared to spend some money and a lot of time at the range.

Or, alternately, you could just buy a stock rifle that will shoot 1.5MOA and learn how to get closer to the animal before you shoot it. Long range shooting is certainly possible, but it's not easy and takes above average equipment and a lot more practice and marksmanship skill than most hunters possess. Consider yourself fortunate that you have a place to shoot past 200 yards. There are no ranges in my area that are longer than 200 yards (which sucks because long range shooting is challenging and fun).

Mike