I have a 36X Tasco scope that is giving me fits. It seems that it will not hold zero. By that I mean the scope will enable me to shoot a fairly decent group@ 100 yds and then all of a sudden a flyer 4 to 6" away from the group appears. I changed to a Leupold 6.5x20 to see if the groups tightened and they sure did with no flyers either. So I suspect the scope is not holding zero. Where is the best place to get this fixed? Thanks in advance for any help.--Shuz