A gunsmith is a firearms expert who modifies, repairs or manufactures guns. Training options for this profession include online certificates and career diplomas in gunsmithing. All gunsmiths must have a Federal Firearms License in order to be in compliance with the Federal Firearms Act of 1938. A Federal Firearms License can be obtained by making application to the Bureau of Alcohol, Tobacco, Firearms and Explosives. There are a number of online gunsmith programs that have a great reputation.