I took my only big bore a 416 Rigby to the range over the weekend. I fired 2 shots at 25 yds. to make sure the shots were at least on paper. They were almost touching so I decided to move the target out a bit. Since this is the first time I've ever fired a DG caliber I didn't have a clue as to what distance it should be zeroed at. Hence the question. What is the optimal / recommended distance at which s DG caliber rifle should be zeroed?