I've got some 4759 loads made up with the 506gr. (WW) Lyman sabot slug. I had to cut the compression section off the red field wads. I suspect gas blowby will hurt performance. Just not enough room in a 2 3/4"hull.
The 4759 loads are a good fit for round balls with minimum wads.
Guess I'll have to try for proper fit in 3" hulls- got some 3 1/2" I'm shortening.
A pure lead .715" ball weighs 1 1/4oz, or 545gr. A WW .715" should be about 520gr.
You're on the right track, smoke.
-------------------- Daryl
"a gun without hammers is like a Spaniel without ears" King George V