Needing some help locating a gunsmith with a 10mm reamer to convert a .40sw barrel to 10mm casing. Can anyone give me some contact information to try to find someone to do this for an H&K USP 40? From what I understand the factory barrel is difficult to ream due to H&K's treatment, but aftermarket barrels aren't easy to come by. A carbide or tungsten reamer I would think would suffice, but not sure. Any advice or information, please let me know because this is really my only speed bump in this conversion. Thanks