Been doing some work on this. The only bullet that has given me acceptable accuracy results is a bullet that drops .357-.358 out of the mold. That would be my Lee 124 grain TLTC bullet designed for the 9mm.
I've also tried my Lee 168 grain semi-wadcutter, and the Lee 105 grain semi wadcutter. Both of these bullets must be sized before being shot from any of my guns when conventionally lubed.
The 124 grain TLTC bullet measures around .359, powder coated. I then size it to .358 and it shoots good out of my 10" Contender barrel. So it only gets sized once, very lightly. I can shoot that bullet unsized in all my guns except for a 380 that I used to have.
Those semi-wadcutters come out of the toaster oven measuring well into the .360's. Sizing them down to .358 and shooting them at 50 yards gives me groups about the size of a toaster oven.
I could have easily covered the 50 yard groups I shot today with those 124's with my phone. All this shooting was done with iron sights from a rest.
I believe it hurts a bullet to size it too much. The 124 is the one on the right. These were all cast from the same alloy.
The semi-wadcutters shot fine out of my Taurus 357 revolver at 7 and 10 yards.
Long story short - I will be using 9mm molds for powder coating my 38/357 loads.