I'am not new. but not old ether. I am billding a rifle to Hunt wight tail deer. And to shoot to billd up my skills to shoot beter. I am looking for a caliber in the (SHORT ACTION) that will kill a 120LB-275LB wight tail deer at 600 yards? I know that harvet bullets at impat. Haf to go grater than (1950Fps to expaned!!!) Or the bullets act like a FMJ. I am not shor about Energy (ft/lb) I need. I think 800ft/lb I think of 243 win or 7mm-08. you tell me. UPDATE!!!!!!!!!!!!!!!!!! I live in the MISSOURI flat farm land syobins & Corn. I am bilding a custom rifle off of a Savage Varmit short action with a small shank. I wont a caliber that i can shoot 20 rounds a in a day and not HERT so no Magnoms. and till kill a deer to a 600 yard Limit. how a bout these 243win,7mm-08,6.5x55 I am leening to the 7mm-08.