I use a Leupold bore sighter and it works well for pistol and rifle scopes and iron sights. The only "if" is that the crown on the barrel has to be square. It also needs more to bite on than shotgun muzzles, but anything else it works fine. When I finst got it I moved it up and down on the crown to see if it changed the sight picture, and amazingly enough it always is the same. And I have never had a sope more than about 1.5 inches off center at 50 yards with the first shot. One scope I had to shim, and had I not used the sighter I would have spent a box of shells just finding out where the gun shot. For $40.00 it is a bargain, IMHO.