Thanks for the comments on the wads.

I had been thinking of what to do with wadding in these cases. With today's BP being -not so much- as hot as that found in the nineteenth century, I wanted to maximize powder room. Also as I had a mould that threw .666" pure lead balls *which were undersize a tad for the gun I was working with* I wanted a good gas seal for consistent pressures/velocities.

I'd had a talk with Lewis Drake about shooting the sixteen bore rifle and he gave me good advice:
Get a good seal.

I'd gotten lots of advice from others to use felt wads, I'd always figured that the pressure of combustion would wrap the wad around the ball -decreasing the outside diameter- of the wad. The donut shape solution followed the day I was packing up for my friend's ranch and a shooting session.
Picking through a drawer of punches I saw a small one and the idea hit me to take advantage of the shape of the roundball as a wedge to maximize bore contact.

Really it works great.

If I get a moment this weekend I'm gonna ditch the house and head out to the ranch for some bore rifle shooting.
I'll post something if I get chrono readings.

Tell me more about that wad lube.
What's cleanup like after a shooting session?
The WonderLube is pretty amazing stuff, I don't get any rust or corrosion of any kind from the powder residue, which stays soft.
You guys ever use that stuff? It's yellow and smells of Camphor.
How would you compare your recipe to WonderLube, besides being available whenever you want it, and much cheaper than commercial wad lube?

--Tinker