Tom- in 10 bore, you will be at the same point I was with my 12 double. I started with heavy, highest velocity shot loads and went from there, keping an eye on pressure - case feel, action opening, primer appearance, wads loosening, that sort of thing.

I don't have the exact weight on #4 buck - maybe someone else can help. I think it's 22gr. - but not sure. I will use that weight as I think it's close.

The loading I am looking at in Lyman's book is in 3 1/2" Remington SP Express w/composite base wad, WW 209 primer + 41 #4's (902gr.): wad column = Power piston - + shot and 46.0gr. Blue Dot for 1,336fps - listed at 10,000LUP.

Considering a 10 bore round ball in pure lead weighs 200gr. lighter than the buck load at 700gr., about 650gr. in WW alloy, I'd start with the above load.

Some of the other powders & loads with merit delivering decent speeds to start in 10 bore are:

:Fed case - WW209 - 40.0gr. SR4756 - RP piston + .125" card - 15 # 00 buck - about 750gr. total at 1,283fps @ 9,500LUP

:same case - 45.0gr. Blue Dot - same wad and shot - 1,263fps at 8,800LUP.

:Rem Case - WW209 - 38.0gr. SR 4756 - Piston wad - 14 00buck- about 700gr. - 1,268fps @ 9,200LUP

:same case - WW209 - 43.0gr. HS6 - Piston wad - 14 00buck - about 700gr. @ 1,311fps - 9,600LUP.

Hope this helps you get started.