The gunsmithing hobby encompasses a wide range of skills; one of the most challenging to perform in the home shop is barrel rifling. If it's something that you're interested in attempting, these videos should give you some useful ideas and a nudge in the right direction. If you try it, don't forget to post pics of your efforts!
Homemade barrel rifling tool by Clint Westwood
Homemade Rifling attachment for the home lathe by Waffenschmiedin x
Simple Prototype Rifling Cutting Tool by JaycubL
rifling 003 by Käyttäjän cskeju kanava
Muzzleloader barrel rifling bench by lastkingopoland
Push button rifling - making a rifled barrel by Gunsmithing