Hey buck - good for ya. Have fun and good luck.
I definitely have to 'second' stimpylu32 on his recommendation to stick to factory or listed loads with H110/WW296. Winchester specifically states to use their recommended charges with their powders but unfortunately, they are all maximum charges. This is fine for huntin' and the like but it's not so great for lower level plinkin' loads. Anything less than full power can be attained easier with faster burning powders. H110 and WW296 do not lend themselves to squib or less than full charge loads. The same would apply with whatever the cartridge.
I use both H110 and Winchester 296 in my 357s and 44 magnums. I shoot 200 gn swcs in the 357 and 300 gn swcs in the 44, each over the factory or recommended loads for that bullet weight. Both are maximum book loadings and they are so effective and accurate for me that I consider each the hunting load for each gun. Plinkin' and just shootin' on the other hand calls for lighter loads, which causes me to powders.
You also mentioned the economy of your choice of powder - good thought, once you find the right loads for all the situations in which you would use those calibers. However, you may wish to consider other powders to start with that will allow you a usable range of pressure and velocity at less than max blasters. I have Unique and 2400 powders on the shelf next to the 296 and H110, and others; each has their own application. HTH. Mikey.