[chingalla]

Does anyone know who does this conversion? From my understanding if one has a .357 mag blackhawk it requires only reaming of the chambers? I tried several searches but no solid answers...

[gb6491]

A Google search turns up this for Bain & Davis (perhaps they still do the conversion):
Bain & Davis Gun Shop
(626) 573-4241
307 E Valley Blvd, San Gabriel, CA 91776

You could also try contacting Lee Martin (http://www.singleactions.com/contact.html). He's done the conversion (http://www.rugerforum.com/phpBB/viewtopic.php?p=158905&sid=69bd7c49c78a158d5cc5071d1e9f7c29) and might be able to answer your questions about it (and know where you can get it done).
Regards,
Greg