Gentlemen, my father is new to hunting and tried to sight his shotgun in today. He consistently shoots to the left, actually it doesn't matter what weapon he uses. When I shoot his weapon I am pretty much dead on with the optics. I had a troubleshooting sheet somewhere and can't for the life of me find it and have surfed the net a bit to get causes for shooting left, he is both high and low, but always left.....Any helpful tips would be appreciated.