do it yourself I say
http://survivaltopics.com/boresighting-a-rifle/
The thing that trips people up and I see it all the time.
when bore sighting and you have the bore on target, you adjust like this
If cross hairs are above the target, you adjust UP not DOWN.
If cross hairs are right of target, you adjust RIGHT not LEFT.
Its the opposite as when your shooting to move the groups.
I have seen many people say, hey, the cross hairs are high, then move down and keep moving down till they get to the end of the adjustment, then say its a mounting problem.
Nope, they went the wrong way!
Use blue loctite on the screws too.
Good luck.
First time I ever bore sighted a rifle, I did just that and was wondering "WTH" lol