There are alot of .350 RB moulds available. Yours is an odd size. .356 is (MM, but most 9MM moulds are round nose bullets. Larry Callahan can make one in that size. It is the scissor type that makes one ball at a time.
I was looking for a couple hundred rounds or so.
I had a handful, and my one .36 seems to favor it with a .18 patch. I’m going to buy some thicker patches and try .350 balls, but if I can get some .355 that would be great.