hi. can some one help, my son has the 1187 rb ,he had it drilled and taped for a scope, 7 years ago, its shooting flyers , what should i look for,he just called me,it was shooting to the right,so he adj the scope, now at 50 yards, still flyers, hes tryed rem 2 3/4- and 3" same thing. thanks for looking. help.