Here is my entry.
It is a 3 part design which comes apart for cleaning. The bands were glued on using loctite. Shrinking them in place would have been better but I over bored it so loctite was a good option. The trunnion is held in place with two 10-24 cap screws. The trunnion pulls the breach plug against the shoulder inside the bore holding everything together.
The DOM tubing was used for the barrel with the piece of bar as a breach plug. The wood was used for the base.
Here are a couple of pictures before paint. Ill get a few posted with everything painted in a couple of days.
It isnt much for accuracy. Much of the inaccuracy was due to roll of the ball. If the ball stuck where it landed it would have been great. Most of the shots hit with in 10ft of the stake. The second problem was the difficulty of accurately measuring small amounts of powder. It only took 15 grains of Fg to get it to the stake. The first shot was 60 grains and it over shot the stake by around 150 yards.
I did get one good shot at 17. It bounced and hit the stake then stopped. If only I could have done that for every shot. The total of the 5 best is 764.