hi as the guys said make sure the up is up and down is down. the easeist way is to bore sight the gun, that means placing a target on a board at say 30 meters. take out the bolt, look through the the bore (keeping the rifle dead still) till you see the target in the bore. (still not moving the rifle) then zero sights in to that target. if your rifle has not moved then you must be on the board. I have a C Z rifle with a scope, but the scope on that is off center. if you put a line down from the scope centre to the barrel it does not come to the barrel centre. i know that so i can get a 3 bullet group on a five peny at 75 meters . it drives my club mates mad lol.
be lucky John