Look at the ballistic table below. There is absolutely no reason for those continual, useless, energy wasting arguments about "this" versus "that" type chamber in hunting rifles. From the .264 Win Mag to the .338 Win Mag they are all within .5 MOA with one another with popular bullet weights. Trajectory differences are way less than any hunter can shoot, or even what the accuracy potential of 90% of hunting rifles is.  Looking for your first hunting rifle?  Just buy any 6.5mm, 7mm, or .30" calibre that speaks to you when you shoulder it. With appropriate bullets it will make a perfect hole in exactly the same spot as any other one at the same distance.

 

There is no practical difference between the 7mm Rem Mag and the .303 Brit or 30-06 or whatever at ethical shooting ranges. (Even for those ranges some unethical shooters do target practice on live animals at there still will at most be 1 MOA difference). All of these will kill your big game in exactly the same perfect way too if you put a bullet of sufficient mass and of sturdy construction into the heart.

 

In the table all rifles are sighted for zero at 200 yards. It includes calibres from the "flat shooting" .264 Winchester Magnum to the old .303 Brit as well as the .338 Win Mag - each with a comparable bullet weight for general application. In some instances more that one bullet weight is tabled. Bullets with close to similar design were used for the data research.