Whenever I buy a new gun, be it rifle, pistol, shotgun...I buy 3-4 different brands of ammo, go to the range and let the gun tell me what it shoots best...Even with a .22 the accuracy difference is incredible between brands of ammo...
What is avaliable locally??? As mentioned, a .308 is very popular and all the major ammo companies load for it...Any of the 150-165gr bullets are comstructed for deer...