drift front sight
there are many variables ,was there any wind that day,have you tried any other ammo, usually there are marks on the front sight made at the arsenal from bore sighting, if there are no marks you can start by bore sighting the gun at 25 yards,what i do is pull the bolt,rest the gun on sand bags,or in gun vise,and sight thru the bore 3 in high at 25 yrds should be the ticket,dead on at 150 yrds,and so on,also try some military surplus ammo perferably the same country of origin as the rifle,normally a rifle with a front sight off centerd is caused by a shooter who needed a shorter length of pull,since there is no rear adjustment,as the duke once said ,windage and elevation,man,windage and elevation.