Due to my ageing eyes, I have decided to try a peep on my fire lock. I made it from a piece of scrap 3/16" 01 steel. Ground and filed to shape, then silver brazed to the tang. The hole is 3/32". I could have made the peep hole a little smaller, but want to be able to sight on a deer at early light. I still have to make a new front and zero it in. All adjustment will be with the new front sight. The open rear will need to be removed, and I'm thinking of replacing it with a dummy rear sight cut out so it doesn't interfere with the view through the peep. I figure that way the peep won't be too obvious and I will need to fill the dove tail anyway.