I am pretty sure that the barrel life of a 308 is a little more than 3000 rounds, and that long range shooting is not a hobby of mine, but a passion. I have a 223, in a moa ruger mini 14. I have owned a 7 mag, and a 300 wsm, and shot them extensively at the range, 0 - 500 yards, and to be honest, I don't think they are necessary unless you are unseasoned as a shooter. I will not shoot past 400 at game regardless of situation. and never at running game, so what is the point of a magnum again, the 4 to 5 inches less drop at 400 yards, my max distance.
