This is sorta a power weapon for people in the late game, and would make gunpowder more versatile. WAY to expensive to use early on, though. Especially considering nothing would drop bullets. I feel it would really add to the game.
I'm all for some kind of flintlock gun, pistol, rifle or otherwise. There is a thread around here somewhere called "Guns (All In One) which is about 23 pages long about guns and the like. To save you a lot of rather pointless reading, a lot of people want guns and a few people absolutely hate the idea of guns while simultaneously ignoring the "Mac-10 and Arrows" in the game.
Part of the problem is that the suggestion forum is bombarded daily with suggestions. You made this suggestion last night from the looks of it, and I found it on page 8. I would link you the mega guns thread but I've lost track of it.