I just use a mandrel and stone from the Sunnen set up.

This is for a larger size than you need but 40$

https://www.ebay.com/itm/Sunnen-BL20-619AH-Mandrel-w-Wedge-G/183787002635?hash=item2aca8f1b0b:g:wKMAAOSw8GJcwOCh


Firearms imports, consignments


[Linked Image from i.imgur.com]