I bought a $40 universal boresighter at Walmart this year. I used it for a scope on a .223 and also a.50 MLer. My first shot from both were about 3-4" high and within 2" left to right at 100 yards. I did not use the supplied paper "target" to adjust. I adjusted mine at night. Aimed it at an object about 100 yards away and just dialed the scope so the crosshairs hit the red laser dot. Could not be easier. Took <5 minutes the second time I did it. I was pretty sceptical when I bought it, but I am now a believer.

As has been said before, if someone does not actually do the final adjusting by shooting ammo.........well, shame on them. Just because some people misuse them, doesn't mean they are worthless for what they are intended.