.308. which is 7.62
308...A 7.62mm = .300
400
308 is more than 8 times the size of 37.
lighter bullet and more ammo can be carried as opposed to the 30/06 or 308
No
556
Yes. Significantly.
556 * 556 = 309,136
Both fire the same diameter projectile.
No. Both use the same diameter projectiles.
30-06 because it's a bigger round than the .308 although it might travel slow it has greater impact on the target