I just used Mothers Mag polish on my SR9c barrel and it came out amazing. I recommend anyone who wants a shiny finish to their stainless firearm to use this. I already polished it with some Flitz but after a half hour with Mothers, it came out awesome.
I do not work for Mothers, I just want to share this with Glocktalk. I would not use this on my Glocks because I love the finish that the barrel has on it already. I hope to one day get a Glock 22/23 that I would polish all the metal on the gun. Enjoy.