[Coureur De Bois]

I have Williams peeps on both my RMC's, they're made to fit the flats on the barrel. Had them installed at back of barrel, centered adjacent the touch hole, which creates a ghost ring when you unscrew the center ring, sight in ring. It also obscures some of the flash from the pan. You will need a gun smith to install them, new holes need drilled and tapped.Cost will be around $50.00 for sight and another $50.00 for mounting.
Very accurate sight system.

 

[Coureur De Bois]

Here are a couple pictures of my RMC with a Williams peep.

 

[Coureur De Bois]

If they make a peep that mounts back near the tang without you having to drill holes, that would be the way to go.
I could of mounted the Williams where the original open sight was, but I wanted something closer to my eyes to take advantage of the ghost ring effect .