| Callum a musket in once upon a time land was essentially a tube with a hole in it, you just replaced the wicks, later match and flintlock systems were interoduced. Maintainance was pretty simple. A bow, especially a good quality longbow on the other hand had to be oiled dailly and strings had to be replaced...
As for manufacture a bow would have been easier to produce - there was no "manufacturing" until the 18th century, prior to that everything would have been hand made, a musket is a lot of work, the barrel alone is a nightmare - forming a tube prefectly straight, and welding it closed without forming any welding spatter (easier as the techniques involved didn't use a torch... but still not fool proof). If once it was made and tested the barrel wasn't true enough they would scrap the barrel and start again...
On the other hand a bow is cut from a straight bit of tree and planed into shape |