That's looking good alright. All of my Officers Models shoot very well with my standard loads (light Titegroup or Universal powders). I've seldom gone through the process of optimizing a load for each gun, but that's where you will wring the last bit of accuracy out of any gun. They're pretty amazing revolvers.
2.7-3.0 grains bullseye and a 148 full wadcutter, you will have all 5 in the group if you do your part, really. Plain base wadcutters shoot so close to hollow base wadcutters so I cast them on a 6 cavity Lee mold. That is most likely too light of a charge with unique to be consistent. I mistakenly loaded that light with unique ( was suppose to use bullseye) and I could literally see the bullets in flight going to the target at 25 yards. You are probably getting sooty cases from blow by as the low pressure doesn’t expand the case to seal it. Just my .02
I blew up a ruger sp101 revolver in 357 mag. using bullseye a few years ago. I've got a walther 32 auto I'll use bullseye with but that's it. The load I used was a minimum load from oregon trail's manual. I've got another unique load .3 grains heavier ready to go. I was gonna go to the range today but I went to a local prairie dog town and shot a couple at 483 yards instead.
arjay: I'll try that load eventually. I'm using 158 grain hardcast semi wadcutters too. Do you know how many fps you're getting? I've got a chronograph but at this time of year with the sun low in the sky half the time I can't get a reading. I hear that 800 fps is about right.