Best guess is the bore sighter does not have enough height to allow the use for such.
Worst case, just use a small mag flash light down the bore (upper off the lower and the B/C pulled), pick a spot on the wall a ways away, and bore sight the scope in on the dot. If you are only shining around 20 ft away, sight the scope in about 1/2" high on the dot. This will get you on paper at 50 yards, and you can fine tune under live fire from there.
Posted By PlaymoreMinds:
'Twas not the <cough> sweet and innocent <cough> PlaymoreMinds...
<---skips away in frilly skirts to Candyland, leaving gutters and snorkels FAR behind.