Imagine being out in the wilderness for six months to a year, or more. Driving rain, wet snow, steaming summer days, misty nights, scrambling up and down rocky hillsides and over logs, etc. Crossing creeks and rivers every day, sleeping on the wet ground and every minute dragging a ten pound five foot long rifle along with you! You would do your absolute best to keep it dry, clean and oiled and dread falling on it and breaking the stock, but the days and miles would surely take a great toll on your rifle.
I'm sure that Boone and his contemporaries would make a beeline to the nearest gunshop when returning from a long hunt and at the least get their rifle freshed and otherwise made serviceable and if they had a profitable trip they probably traded for a new rifle.