I plan to run it in cylinder bore shotguns. A round ball has very little bearing surface so I wouldn’t be worried about sending a .735” ball down the barrel.Lyman .735 is not what you want. That is their Brown Bess ball and while it will fit in a brass case, will push your choke out with about 20 shots. If you have a modern rifled barrel for a strong action, you can get it to shrink down to fit, maybe. FWIW
How come you don't use the bp brush wads or GS? the cup should hold one of those pretty well. I've cut the brush wads in half, trimmed them and stuck a gas seal underneath, they work pretty well for the .715' RB's if I remember right - been a while. I started sticking with the smaller one so I could use the full wad protection.I use my .735 in my CYL CHOPED AND RIFLED barrels only. Load with a wad with pedals removed. Played with various cards to make up proper length. So far nothing fantastic accuracy wise but useable for sure.
Im wanting something I can use thru my choked guns next.
If ya would like to try some .735's drop me a PM. Maybe we can work something out.
CW
Yep, I used the cups to hold center then stack and pack, keep'em tight and they fly right..On top of the cards / wads you want to place some filler (I use COW) under the ball to form around it to keep it square to the bore If the ball / card stack tilt to any side it will not fly straight.