"Do you know why the current calibre for most nato guns is 5.56mm? yes partly because its smaller, partly because there is less kick, but also because its less

"Do you know why the current calibre for most nato guns is 5.56mm? yes partly because its smaller, partly because there is less kick, but also because its less lethal." This is actually a myth - the .223 was not selected because it's designed to injure instead of kill. The main advantage of the round is that it's light, so soldiers can carry a lot of ammunition on them, but it also has a flat trajectory and is quite lethal within typical combat ranges. You also get the advantage that it's easier to shoot a .223 quickly than a larger caliber - a soldier can put 30 rounds down range with more accuracy, in less time, than they can with a larger caliber.