Well if you use a 50 cal. round it would go around a mile into the air, assuming that the shot was perfectly straight up, if there was no wind and the earth was not rotating it would come back to the same place being it could not break the gravitational pull of the earth. A shotgun slug would go around 5oo yards before reversing course. There is many factors in place, when you change the size and weight of the round you will have very different results.