Newbie question- I am having a rifle built and am torn between getting a 22" or 24" barrel, the action will be .300 Win Mag. I am leaning towards the 22, as I will be using this gun for backpack hunting and would like the shorter length. My question is this: How will the shorter barrel affect the ballistics? I notice that most calculations from the ammo manufacturers and on the Zeiss ballistic calculator site are based on a 24. An important side note- I won't be using this rifle for shooting over 600 yards (unless I get a hell of a lot of practice in.....). I also will only be using factory ammo, as I do not reload. Thank you for any guidance or ideas. This site has been a tremedous help.