To be a really good gunsmith you need to build very accurate rifles every time.
Customers must know and trust in you to deliver an accurate rifle every time.
That is the true measure of a good gunsmith.
To have the ability and focus and knowledge to build accurate rifles.
You must also know when to tell a customer what he wants is not going to work and to give an alternative.
You must have the integrity to give good advice that’s best for the customer. Even if it means you don’t get the work.
You as a gunsmith must understand the pros and cons of different actions and how they work. What to do to make them more accurate.
The best way to learn gunsmithing is by doing a course in machining. Either fitting and turning or toolmaking.
To become proficient in that course and to learn how to work in a metal lathe and milling machine.
Learn how to use various hand tools.
Then seek out a good gunsmith and work under him for 4 to 5 years and learn.
Nothing beats experience.