If you are going to use a low-pressure Unique load, better keep your bullets a bit on the soft side. You may have leading problems if you use "hard" cast bullets at 900-1000 FPS or so. That usually goes away with a stout charge of 2400, but that load is not a "target" load, as I think of it anyway.

I used to use 7.0 Unique in the .41 Magnum for indoor target shooting with the 220 gr. Keith pattern bullet from H&G molds. It always shot reasonably well, but I did not find it terribly uniform. I changed to 231, and wasn't particularly happy with it, either, so I tried some other powders I thought might be more satisfactory in light loads, - Bullseye, 700X, and Red Dot. My experience was they were all about the same (70-100 FPS of extreme spread, depending on the primer). If that doesn't bother you, Unique should be as good as any. I never did find a nice, mild load for the .41 (or 44, for that matter) with the kind of ES I like to see in the magnums.