To be more specific, I bought a zip lock full of .308 ammo but they didn't know what grain the bullets are as it was from some boxes that had torn open in shipment. They're all Sellier & Bellot, they "look" like match grade ammo in the sense that the cases are not knicked, dimpled or discolored. Is there any way by weighing the bullets I can maybe find out what grains the bullets are?