Not a gunwriter but I do have an opinion:
Both will yield velocities north of 2950 FPS in a 24" barreled 300 WSM. The Top RL22 loads, velocity wise will be compressed. H4350 top loads will not, being a bit faster powder. Top RL22 loads will produce a bit more velocity (about 50-75 FPS, over H4350, nothing earth shattering) at pressure. Pick your poison.
RL19 and MR 4000 are also in the same ballpark.
