The liner only needs to be firmly in place, don't over torque it or break off the back end. Be sure none of the liner protrudes into the bore, firing chamber. After drilling the hole put a very light chamfer on it, once the liner is in and it is filed, dressed down, almost level with the side flat lightly peen around the circumference before finish filing it level with the flat.
If it is a White Lighting liner from Jim Chambers it comes with pretty clear installation instructions.
dave