Mongoose,
Have to agree with Bounty Hunter. Going with pre-manufactured (factory) ammo for a rig like you've just purchased for yourself is ********! You'll never get the accuracy possible with fine-tuned hand-loads. Call Graff & Sons or Sinclair International for components. My recommendation is that you get your yourself some Lapua brass and Lapua 250-grain Scenars. Then start with 88.5 grains of VV N560 behind the subject projectile 0.020 off the lands. You should get a mean initial velocity of 3000-3050 fps and **** good accuracy (i.e. sub-3/4 MOA)!
Regards,
Dave