I recently converted a perc to flint pretty easily--it depends on the lock. In my case I just replaced the drum with a vent liner that screwed right in and fit a lock that was the flint companion to the perc lock [some are made identical as to plate/innards etc]...it took a little fitting of the lock to tighten against the barrel, etc. Now, I have another rifle I wanted to convert from perc to flint and found that the particular lock I had used was not compatible with its sister flintlock...I left it percussion.