I am in the market for a 400-600yd gun for deer hunting and a target practice. I have no caliber or manufacture preferences just in the starting phases of looking so I thought I pose the question to all you fellows.
My calculator shows a Berger 168 grain .284" (7mm Rem Mag) at 2,900 FPS carrying 1,006.6 ft pounds of energy all the way to 950 yards. Impact at 1,642.7 FPS.Your caliber needs to deliver at least 1000 foot-lbs of energy at the desired range to kill deer. At 600 yards, it is far and few between the cartridges that still deliver this sort of power. Most non-magnums bottom out before 500. A 30-06 using ho-hum Winchester Super-X in 150 grain Power Point will only have 808 ft-lbs @ 500 yards, while a 300WSM will still have 1,074 ft-lbs., & the 7mm Rem Mag w/ the 150 grain bullet is still toting an ass-thumpin' 1,239 ft-lbs at 500 yards....but its at -40 inches at that range, so you'll have to practice alot. Consequently, it hurts your shoulder and nerves to shoot a 7mag for more than a box of shells at a time. My advice would be to get closer to the deer and shoot a more enjoyable caliber. Like a 7mm-08. It has 1,094 ft-lbs out to 400 yards with the 140 grain bullet and only 25" of drop.
Your caliber needs to deliver at least 1000 foot-lbs of energy at the desired range to kill deer.