IIRC, I used around 4.3 gr Unique to produce loads just a hair under 900 fps with Zero 147 gr JHP bullets. Checking the Alliant Reloading Data site, my velocity was somewhat lower than they get with Speer Gold Dots and their test devices.

You didn't mention your powder charge, the velocity or the data source of your 231 loads. WW data tends to be optimistic since they use test barrels that have dead minimum dimensional specs. Low velocities can also produce big groups since your wibbles & wobbles have more time to effect the bullet while it's on the way down the barrel.

A 125 truncated cone bullet with a wide grease groove will do minor with ease, minimal leading and cost less than 147s.