First of all, welcome! Alliant's web site gives 4.9grs of Unique as a max load with the 125gr FMJ. My IDPA load in 9mm is 4.4grs of Bullseye. When I loaded Unique it was about 4.5grs if memory serves. I'd back off to that loading if I were you, just to be one the safe side. The powder manufacturer's web site is always a good source of load data. It'll help keep you out of trouble. Good shooting!!
Savage