I think RE17 is designed for short magnums so it "should" work, but Alliant's site only show RL19, 22 & 25.
Alliant Powder - Reloader's Guide
The Berger manual lists Re17 for the 284 Winchester with a 180g bullet. The starting load is 40g, almost the same as IMR4350, but 2.5g less than H4350 and 3.5g less than RE19. The 270WSM with a 140 starts at 53.5g for IMR4350, and 55g for RE19. So living dangerously, you might try a starting load of 53g of RE17. Or you might find somebody who actually knows what he's talking about and get a better number. It's your life you're risking, not mine ... Play safe.
My impression is that maybe RE17 is intended for slightly smaller case volumes. It works great in my 6.5-284.