I just received my $7.00 9mm lazer bore sight. I am going to adapt it to a 44 mag. empty case, as the 44 mag. lazer bore sight is about $39.00. For me it will serve my purpose exactly..but. The but is, that it is really just a 9mm brass battery holder that projects a red lazer beam a good distance. Being the cheap sight, the lazer beam is not centered in the brass 9mm battery holder. I tried it out in my 9mm Khar, at about 15 feet the beam was 15 inches to the left and about 4 inches low. Using the adapted 9mm sight in my 44 mag. case I can rotate the shell to match my sight on target. If you want to use a lazer to bore sight a scope mounting etc. you will have to spend a few extra dollars to get a quality bore sight.