Yep, the cartridge you have is fine. I'm really fond of the 7mm Mag myself. When you mention "flat shooting" I'm assuming you have an interest in shooting at fairly long range distances. If that's the case, then in my opinion the cartridge is of less importance than the rifle itself. .308 class cartridges and up are quite capable of taking game at fairly long distances. However, some rifles may not be up to the task. You should consider getting your rifle accurized (new barrel, bedding, trigger work, etc...) if I'm correct about your long range ambitions.