I bought a case of military ball 30-.06 at a gun show recently, however the individual boxes don't have the bullet grain on them. The ammo boxes have a 1963 date on them. Does anyone know what the likely bullet grain is on this ammo? Also, a gun shop owner recently told me to be careful, that shooting some of today's factory loads might be too much for my M1 Garand. What do ya'll think? What is the threshold that I should stay under as far as muzzle velocity? The reason for the questions is that I am getting ready to begin finding the most accurate round for my M1 and need to know what to stay away from(besides Wolf and Silver Bear!) Any insight would be greatly appreciated.