I'm not a reloader, does hornady publish what powder they use etc....? or is that part of the kept secret?
No ammunition company reveals what specific powders they use in any caliber cartridge or load. This is because they buy large lots of powder in given burning rate ranges that they consider appropriate to a given cartridge's requirements, and, using their pressure and velocity measuring instruments,load to a specified pressure & velocity level. The powders they use for this process
may or may not equal any type of powder you can buy in a can at the reloading supply shop.