我看的文章只有講到15碼內雙彈著點範圍是一個橘子, 到25碼的話雙彈著點範圍是一顆西瓜.

"in a target of the size of an orange at 15 yards and of a water melon at 25. "

原始文章連結:

http://www.geekologie.com/2012/03/p...e-barrel-pi.php