Seeing other posts about rims/extractor grooves, is what I was eluding to in my post where I say WW dimensions are good. I should have mentioned I too find R-P rim diameters small with a different cut, and have a strange feel in my progressive. I cut down 9mm into 9x18 too, and doing any final trimming with FC brass has a lot of chatter, rougher results than with others. Can't say what brass formula FC uses, but for both rifle and pistol I find it not to my liking.
Saw CBC brass mentioned, and IME I find the mouth wall thickness rather thick, and can't use it in 9x18. Even with fatter sized cast in 9x19, it can be hard to use because of excessive bulging with CBC. FWIW, over the chronograph I find FC brass to consistently produce lower velocities, all other components being equal. Lastly, I have noticed a slight 'dishing' of CCI brass at the case head, and think this is because of the impact extrusion method used to make the cases, where others use a more traditional cup and draw method.