Re: FYI-> Moon Gander Mountain Shotgun Boresighting
Is it a cantilever barrel/scope mount? Most bore sight systems are calibrated to be "on" when the line of sight (center of scope) is about 1.5" above the bore. If you used cantilever mounts and/or high rings, those bore sight systems won't even be close.
I see this all the time with AR15's and guns with "see thru" rings. If the scope's 2.5" above the bore and the center of the bore sighter is 1.5" above, you can't line the 2 up.
FYI, the Leupold style, "magnetic" bore sighter that attaches to the muzzle with a magnet can be used quite accurately (if your muzzle is square). You just have to center the bore sighter the same height above the bore as the scope.
Bore sighting ain't difficult, but some "clerks" have no idea....