One of my shooting buddies is a retired gunsmith. A lot of what has been listed so far are what he described his job being 90-95% of the time. It is what he calls "Gunsmithing Lite."
IIRC, his most numerous tasts were scope mounting, buttstock pads, cleanings (field and total take down), and trigger jobs. The number one complaint of his smithing concerned scopes. He would mount and bore sight the scopes and explain that the owner would need to refine the sighting at the range before hunting. The hunter would have a bad outing and return the gun complaining that it wasn't sighted properly...and it wasn't, but not because of the gunsmith's work. Either the hunter didn't finish properly sighting in the scope to the rifle or did so with one type/load/weight of ammo and hunted with something completely different.
Beyond these were often minor repairs and cosmetic enhancements.
He said that every now and then he would get in some challenging gunsmithing task, but by and large, the majority of what he did didn't utilize much of his training - hence the moniker of "Gunsmithing Lite."
"If you look through your scope and see your shoe, aim higher."
-- said to me by my 11 year old daughter before going out for hogs 8/13/2011