Your .223 will go 500 to 1000 yards, and you can load the 75Gr Amax to do it great. You'll probably learn a lot more about reading the wind also. You can load for a lot of practice with a .223, and that's what you want. Once you get comfortable, then you can look at what you want to move to - .308, 6.5*55, .260, 6.5*284 etc. Ackley or not?