I buffed out my matt finished Taurus Raging Bull to a mirror reflection finish. It took an 8" bench grinder with the wheels and the side covers removed and an 8" buffing wheel installed. I used a rough cut for stainless then a finish cut. Took about 8 hours total buffing. And lots of disassembly. But I now have a one of a kind. Well almost, Taurus had a prototype bright stainless in .44 mag on their website. I called Taurus to try and get one, and their reply? "We don't make a .44 Raging Bull in bright stainless" Me: Well, you have it pictured on your website?
Taurus: That was a prototype. no one wanted to order any that way, so we don't offer it.
Do a web serch on "Stainless Polishing" and your going to get many hits on suppliers.