you can stretch the .308 out to 1000 but dont expect to get much farther then that. .300winmag will take you to about 1400-1500. personally i would tend to suggest a smaller caliber with heavy for caliber bullets. something like .243 winchester if you dont reload or .243 norma if you do. shooting the 90-100gr. bullets will let you take either of those calibers out to 1000 and are a little more fun to shoot. 6.5 creedmoor or 6.5X284 norma would be my personal choice for long range plinking. savage chambers all of the above rounds in their long range rifles. a remington or savage would both be good choices but since several remingtons have been mentioned already i didnt repeat anything anyone else has said. whatever optics you get make sure they are FFP and at least 30mm tube. make sure the reticle and the turret adjustment are in the same measurement system. either MOA or Mils but dont mix them.