Has anyone used RWS brass in either Hornet or K-Hornet? I've seen the RWS Match and Soft Point ammo for sale, and I've thought about buying some, just to fireform in the K-Hornet chamber. It's pretty expensive, so I'll only go that route of the brass is really good.

I have some RWS brass for my 8MM Mauser. I think it is good brass. I would put it in the same class as Lapua brass I use in my 308

I use Winchester brass for my KHornet good luck with it.

I brought some RWS hornet brass back with me when I came back from Germany after living there for 4 years. The RWS brass is the best I have ever seen for the Hornet. It gives me the most consistent loads in all my Hornets especially the Anschutz's.

I have read and discoverd myself that the RWS brass has very consistent rims which means the cases headspace very consistently.

Slancey,
I shoot a K-Hornet. I have never tried the RWS brass in Hornet, but I have used some .30-06 brass and have made some wildcats on the 9.3X74R brass as well. It is better than good.
I currently am using Winchester brass in my K-Hornet. I uniform the primer flash holes and form them with a bullet seated out further than the throat. When I close the bolt, the bullets are against the rifling and hold the case precisely in place, back firmly against the bolt face, for fire forming. After fireforming, I inspect the cases and only neck size after this. This eliminates any concern over variations in rim thickness. I am headspacing on the K-Hornet's shoulder. I use 10grains of 2400 to fireform.
Neck sizing never causes any problems in the K-Hornet as the brass is very thin and any bolt action can cam the bolt closed or open on a tighter fitting case. Tight fitting cases that are only sized half to 2/3 the way down the neck give me the best accuracy.
Maybe this is more complicated than you wanted.
Good shooting.
The Bearman