I have used a couple of powders with great final results through the years. My oldest load used IMR4350 as well as a 200 GMK. It shot very correct, but I'd loaded it as twin objective Looking / Focus on load. I switched to RL22 as my principal 300WM powder https://damienajivb.blogolize.com/The-Definitive-Guide-to-hodgdon-h1000-gunpowder-53509102