I am no expert, and have only reloaded 400 rounds so far in my short career but I am using Unique powder and Berry Double Struck Plated bullets.
I shoot the 115 gr RN Berry bullets out of my Sig P226. I use 5 gr of Unique and my OAL is 1.154-ish. Not a single issue thus far. I find 5 gr is very mild on recoil and pretty accurate.
For what it is worth, at least I can tell you that 5 gr of Unique functions fine with 115 gr bullets.