Michael there are a ton of options when choosing caliber action or make for a competition rifle . zero to six hundred yards .223 to.277 calibers do a fine job. If u want to be able to reach out to the one thousand yard mark accurately, I would be more inclined to go with .284 / 7mm through .338 calibers. There are a number of conditions that come into play at that range. First is ballistic coeficient of the bullet you are using. Next spin drift, then bullet drop, being able to compensate for wind drift. To be truly accurate. Having deep pockets also helps because your gonna spend a boat load. Good luck with whatever you choose. My personal favorite is a Springfield M1A super match 7.62x51 or .308 whatever you like to call it, topped with a custom bulllet drop compensating turret scope.