If you have access to a good gun vise you can shoot one shot with the crosshairs on the bullseye. Then if you can anchor the gun with that sight setting (crosshairs on the bullseye) you can adjust the scope to put the crosshairs on the bullet hole and you are almost perfect. The big secret is the gun has to be secure so that it does not move when you are adjusting the scope. I have done this several times and it saves a lot of shooting.