Do you want to become a gunsmith? You will need to work on both theory and practical gunsmithing study. You handle guns with your hands. However, you need to understand all the pieces and part of a gun to understand how they work. You need to understand the theory of how firearms of different types work. That covers the theory. The practical side is what is most important. Once you learn the parts of a gun in a book, you need to take a gun apart and learn how to put it back together. In addition, it should work once you get it back together. Without that practical side, you are not going to be an effective gunsmith.
Becoming familiar with common gunsmithing tools is part of your study requirements. There are tools that you will need to be a gunsmith. Some of those tools are useable in other professions. However, only gunsmiths use a few items. You will need to know what these tools are and how to use them properly. That is all part of practical gunsmithing study. You can get the list of tools you need from a study course. You will also get access to detailed information on the way to setup a working and storage area. That knowledge will get your workshop setup and orderly.
You will need to become familiar with various types of firearms. If you walk into any gun store, you can see a wide range of guns including rifles, shotguns, pistols, and revolvers. Each works with a bit different configuration of parts. You need to know how each type of gun breaks down and the way it goes back together. Part of your practical gunsmithing study is to learn the anatomy of each type of gun. You will first learn it as theory. However, at some point, you will need to access each type of gun and take it apart yourself.
Making common repairs is part of being a gunsmith. Once you know the parts that make a gun, you need to know about the different types of problems that guns can have. You may find that a gun has accuracy problems. It might be a problem with the sights or it could be a bore problem. That is just one problem that a gunsmith has to diagnose and correct. You will need to learn how to do a proper diagnosis and find the problem. Once you make the repair, you will need to learn how to retest it safely with dummy and live ammunition. Part of your practical gunsmithing study will include learning how to handle ammunition safely.
You should work to find a working gunsmith with whom you can work. You can learn a lot from books and theory. However, there is nothing like real world experience. Part of any practical gunsmithing study must be spending time with an experienced gunsmith. It will give you access to a wide range of firearms and time to ask questions of the master.