I have used Unique for just all pistol calibers (9mm, 38 SPL, 357, 45 ACP, 44 Mag). I've even used it for Cast boolits in my rifles at a lower velocity (.308, 30-06, 7.62x39).
However, that is mainly because years ago I bought a keg of that powder because I heard it could be used in this way. Now that I am a bit older and more experienced I would not do that again. Unique is a dirty powder. It can be used just about anywhere and there are recipes for it all over the place, but it will be used when I cannot find anything else from now on honestly. I use HP38 now for pistol whenever I can or Bullseye. I do not have a go to for rifle but based on this thread I will most likely start using Varget. Thank you NES community for that information.