Thanks, all. I'll take a close look at that laselyte. As Sheridan says, "They are good to have, when you "need" one !" I've been caught needing one a few times -- have to travel to shoot (and pay) and had a couple bad boresights by so called gun smiths between me and my friends. Would have saved us some grief. I get that they're crude tools and are just intended to get you on paper.