Hi Rupskin,
I paid Bruce Gray of Gray Guns gunsmithing to convert it to 10mm. He was running a program that he publicized in the SIGforum (
http://sigforum.com/eve/forums/a/frm/f/430601935) to convert full stainless SIG P220s to 10mm.
I'm sure if you pay him enough, he'll do one for you!!
If he has any barrels left over I guess.
- Thomas