If I was limited to one centre fire rifle cartridge for all my shooting, it would be a .308. Used only a .308 during my "formative" years as a hunter, and will always have at least one on hand. My current .308 is a an old Sako Forester. Have also owned and hunted with a Brno ZKK, Rem 700, Savage 110, Savage 99, and a Valmet .308/12 combination gun. They all worked well and shot accurately.
