Depending on which bore sighting tool you got. Should you become frustrated with it, just bust rifle in half, secure top half (upper receiver) so it does not move, then remove bolt carrier group. Then you can simply look right down the inside of the barrel, your eye will naturally center in the two circles of one light and one dark. Note where it is pointing and then check optics and dial in to match. Poor mans bore sighted! Hah!
