GK:

I purchase dies from Lee. Last I checked they are $25.00 per die, you pick the diameter {custom}.

For reduction from .375 to .369 {the groove diameter of my 146 for example} I use a .372, .370 and two passes thru the .368 die. I then get a .368 bullet.

For your 9mm {.357 diameter???????} I'd us .366 diameter bullets and get dies in .362, .359 and .356 and run them thru that and see what you get. I like the bullet to run "on" or .001 under groove depth, depending on case neck diameter. Your case neck clearance in your chamber must allow the bullet to release form the case.