Balls sold a "16 pounds" will probably range from 15 lb. 12 oz. to 16 lb. 4 oz., more or less. Since drilling (finger and weight holes) can remove as much as 4 oz., the ball can be 16 lb. afterwards, to make it legal. (Personally, I'd like such a ball to be 15 lb. 15 oz., after drilling, because absorbed oil can make it technically illegal at places, like Nationals, where they weigh balls.)