I loaded some 9mm powder coated boolits to test. I used an MP mold which is a 130g. round nose. With my alloy and powder coating they weighed 140-141g. I used 3.6 g. Of Titegroup.
The mold drops right at .356 and I powder coated them and sized them to .3560. I used the shake and bake method.
The group was 10-12 inches with 3 bullets keyholing that brought the group out to 15 inches. The pistol chamber will not take a larger bullet.
So what would you try to get a powder coated bullet to group well?