I prefer ball powder in small capacity rifle cartridges like the .223 and .308, so for me it would be Win 748, but H-335 is what I have on hand at the moment. When I load heavier bullets in the .308, I select to a slower burning powder like W-760/H-414. The idea of using a single powder for two cartridges is slightly flawed though; because powder is consumable, and because most powders are similarly priced regardless of burning rate,there is no saving by selecting only one type. In general terms a .223 will get about 270 rounds per pound vs 155 .308s; subject to the selection of bullet weight and powder choice for each cartridge. IMHO, choosing the best powder for each application produces the best results.