Daryl-

I have yet to shoot over that third rear sight.
I'm working with the modern formed brass sixteen bore hulls to neck them down (just a tad) to take the roundball. As I just got a new mould hoping it'd throw balls that are more round than my 19th century vintage pincher-type mould (it's a lyman -- not perfect, but good enough), the balls from the new mould are a tad bigger in diameter and I want to run them to see what kind of difference that all makes before I commit to dimensions for my dies...
Once all's sorted I'll get those sights sorted too.
The notches are soooo tiny, they're very difficult to use at this point and I really think that they were simply struck with a center notch from which to file down to regulation height.
I'll just see what happens as I get the loading gear together for that nice little light rifle.
Over a hundred yards it's a pretty darn flat shooting rifle though. After a lot of research, questioning, referencing... I settled on a 2-1/2 Dram FFg starting load and I was pleased. I haven't chronographed that gun yet, but from the sound of things I'd guess I'm getting velocities in the fourteen hundreds to fifteen hundreds.
The gun hits hard and quick and the roundball has the sizzling hiss of supersonic frieght train performance.
If I can ever get my chrono to work for me when I'm shooting the bore rifles I'll be in business and will definitely report performance.

These muzzles sing such a sweet tune...

--Tinker