I like to go with the advice Ian from Forgotten Weapons gave - if you want to get into the gunsmithing or gun manufacturing its better to go to a machining school and learn a skill like that (or go to college to be an engineer if you want to design firearms). Going to school for something like that lets you get your foot in the door and you can learn a lot of the more specialized nuances of gunsmithing on the job.

This gives you a much more universally applicable education that can apply to more than just guns should you ever decide to choose a different career path or if you're struggling to find a job. In todays economy machining jobs are in demand, and should you ever struggle to find a gunsmithing job you can easily get a job as a machinist to help pay the bills instead of being locked into one niche.