Both powders will work but I'd expect the 4350 would be a little better - check load manuals. Like Bearcat, I don't use 150's but for years have used IMR 4350 and 180 gr bullets ( Hornady, Speer, Noslter PT) for a very accurate load and good hunting results. I think I use 54 to 55 gr, Rem brass and CCI or Win large rifle primers. Check load manuals to be sure. I've used 4350 w 150s but its been a long long time and I don't recall the performance. Another powder that works well w 180 gr bullets is IMR 4831.