Philip,

Welcome to the world of Double Rifles, and congratulations on your purchase.

Try a search of the double rifle reloading forum, using the reference

9.3x74R

You should get some results. If not re-post, as there SHOULD be reloading data on that cartridge in the reloading forum. I have a 9.3x74R and have a load, but use Aussie Mulwex ADI powder. Also it has adjustable regulation so I adjusted the barrels to suit the accurate load, instead of the other way around.