Any of the above works, '06, 243, 308, 270, and 6.5 creed. They will all kill. Depending how much you are going to shoot, walk around, look at what ammo is offered for what you want to do. (target, deer...). You will see a wide range of prices between and within cartridges. If you aren't shooting more than 300 yards, my choices would be creed or 243. Everyone makes these, can find ammo anywhere, little/no recoil and kill deer as well as anything. Also, don't buy a gun from F&S, support your local gun store. Most treat you well and will have you coming back for more guns...you can't just have one.....