Back in the late 70's through the 80's I had a S&W Model 39 and spent a lot of time working up loads for it. Solely for accuracy and not stopping effectiveness. I used 124 gr FMJ with Unique but cannot recall the exact powder drop. I think it was on the low side, perhaps 4.6 gr. That pistol was amazingly accurate with handloads and one of the few guns I really regret selling.
Alliant lists 9mm recipes using Unique from 4.3 (147 gr subsonic)up to 6.3 for a zippy 115 FMJ. So your memory is probably still good.