I need some help with my grandsons Mossberg maverick. We took it out today and it is shooting about 3" right at 20yd. Both my grandson and his dad shot it and it shot the same for both of them. I don't know much about shootguns. Is there any way to change the POI with out putting new sights on it. We tried several different types of shells between 8 and 5 shot it seemed to be about the same with all of them