The 1790 {Book Of Trades} referes to several trades to building a gun ,for the barrels these are produced by a barrel forger, the lock by a lock maker and the the stock by a stocker.and like wise the engraver All of these trades worked for several gunmakers who then built the the gun from the parts of the trades mentioned ,in other words they were builders of what we would today call kits.
The gun smith is known has a repairer of guns this became more popular in the breech loading period from the pin fire onwards
The journeyman gun maker was mostly an apprentice just out of his apprenticship who travel from town to town and working part time for several gun makers.Records show that most of these journeymen lodged at the local workhouse,when he had saved enough money he would start a business of his own which depended on the gentry and gentlemen farmers of the area who would be his clientele.
Enclose are some of the charges he would have charged from a 1845 bill
Cleaning a d/b gun and repairing the stock 2 shillings 6 pence
Polishing barrels, cleaning locks ,stock and furniture fit a new nipple 3shillings 6pence
New ramrod 3 shillings
Accessiors
4lb of gun powder 10 shillings
1 bag of shot 7 shillings 6pence
2 sheets of best white wadding 2shillings 6pence
1box of anticorrosive caps 3 shillings 6pence
Feltwad
A Flint Lock will not secure a chicken house door