toolmaker you know your stuff I need the simplest method I have a .22 barrel 5/16 id 1/2 od its 18in long I am not going for perfection just functionality and legality so if the hook will do the job can you help me build one I saw a youtube vid with a guy using a 1in piece of hack saw blade attached to a rod and repeatedly pushed through the barrel to cause groves is this like the hook method well if you come up with a plan I am all eyes and appreciation thank you for any help on this