The term "gunsmith" is as self descriptive as the term "machinist". Very simply, the gunsmith is a technician, an artisan, or a repair person that works on guns. He may have a specialty: sporting rifles only, sporting shotguns only, military/police weapons only, sporting handguns only, competition guns only, etc. He is likely to specialize in one aspect of the shooting sports: barrel/action/chambering work, accurizing work, stocks and stockmaking, engraving, refinishing, etc. Today you will rarely find a gunsmith that will tackle any and all repair jobs. The era of specialization is deeply ingrained in our sport as it is in medicine, or accounting, or any number of construction trades and professions.
The old-time concept of a rural gunsmith is as a jack of all trades. He could repair most anything anyone brings into his shop, from a malfunctioning shotgun to a sour shooting varmint rifle, to a handgun that jams frequently. He is skilled at woodworking and metal working using basic hand tools and limited power tools. He can conduct repairs ranging from removing and replacing factory parts to making and fitting parts. He is likely to be an avid shooter, hunter, and reloader, and started his professional pursuits as a hobbyist.
The gunsmith may have a background as a skilled machinist, or woodworker, or mechanic specialist. If he didn't start with these skilled trades, he picked them up somewhere along the way by previous employment, trade school, or vocational training courses. His love of guns and the shooting sports is what made him follow this line of work. The skills and knowledge that he needed to work on guns came along as he learned to become proficient at operating lathe, mill, grinder, sanders, and saws. Welding, brazing, and heat treatment and knowledge of metallurgy was picked up in working with metals and gun mechanisms.
For all his skills, knowledge, and abilities, the industry pays quite modestly. It's tough running a one-man gunshop and many operators in the populated parts of the country, find themselves unable to compete with the gun and ammunition sales of the local Walmarts. The super srting goods stores often dominate local gun repair work. Offering repair or custom gun work is the only way to stay in business. It's an activity that demands more business skill than technical skill be sucessfull. Retail sales of gun related accessories is often more profitable than gun sales. The modest income potential tends to frighten away the younger people interested in this work. It tends to appeal to the older, closer to retirement age individual that is concluding an established career or has attained financial stability. It is frequently taken up by men that have retired from one career and are seeking modest retirement income.
So, what is a gunsmith? First and foremost, to be sucessful, he should become a specialist. He should have a background in machine work, machining, and woodworking. He must be an excellent businessman, and most importantly, he should not expect to get rich in pursuing his love of gunsmithing.
