I put a Williams FP peep sight on my .50 BP barrel. The front fire sight looks like it might be a tad short for the set up. Anybody know what height it needs to be or will the one that's on there work? Thanks.

I'm using the factory front with a Williams aperture rear on my 209x50 tube with no problems. Try yours before spending more money.

Brownell's has a handy sight height calculator if you need to change the front sight.

http://www.brownells.com/aspx/NS/GunTech/sight.aspx