1. You took the shot so you should put in the time to do a through search. Don't give up till you're sure.
2. If any shot doesn't hit where you think it should have I believe a "confirmation" shot needs to be fired before shooting at game with the rifle again.
3. If you did hit him then it may be time to find a new round/load for the ML. Some just seem to leave better blood trails and make life/hunting a whole lot more enjoyable.
4. Hope you find him and he is still good.
Mitch