I’m guessing some of you guys have some experience with slug guns. My dads heading to Illinios late next week for their gun season. He has a savage 20 gauge that he wants to take and I can not get it to shoot well at 100 yards. Spraying every where. Is 100 yards a difficult shot for a slug gun? What expectations should I have for it. Shoots well at 50-75 yards then goes to hell!