Quality is the key here. Good steel and good flints last a long time!
The state park that I volunteer at has a number of muskets that are routinely fired for blackpowder demonstrations. These get beat severly due to different shooters, and differing ideas on how to take care of a flinter. Most of the guns are 20 to 25 years old and are Pedresoli and Navy Arms Brown Bess and Charleville muskets. Many of them are shot 5 to ten shots a day, daily for 20 years. (35,000 rounds on one weapon!) Yet, as "gunsmith" of the fort, I have only had to change 1 frizzen on 1 musketoon.
My own fowler is running upwards of 15,000 rounds, and my rifle is in the 7,000 round class. I have not had to even reharden either of these frizzens. /ubbthreads/images/graemlins/cool.gif
(edited because of a glich in my system - reran the numbers) :redface: