I've used 5744 in obsolete levergun loads with varying success, but I've never seen that formula before. Hodgdon has a similar method for "light" loads using H4895: multiply the maximum H4895 load for any given bullet by 60%, and use that as the light load powder charge. I've only done that in 7mm-08 loads for my kids but I may contact Hodgdon about doing something similar in the .416 with cast bullets.