Doable, but not ideal or optimized for the cartridge.
I find RL33 a bit slower than N570, and better suited for .338LM or Improved (it was my go to with 300s for the latter). RL50 is even slower so it doesn’t really make sense to me in a .300NM, but that’s just a hunch. I think RL50 is more popular with 37xc and 375CT, but I don’t shoot either of those these days so not direct experience.
.300NM is a lot like a .300WM shooting heavies or a .338LM shooting 250s, so lots of powers in that range from H1000 & Retumbo, RL25 | 26 | 33, and N170 | N565 | N568 | N570. And then weirdly I have one barrel I shoot 178s with N165.