I bought an "premium lapping kit" from www.easypckits.com and used those sandpapers to do mine. The kit comes with everything from 400 grit to 2000 grit, and in small sizes perfect for using on guns. Basically I didn't do a whole lot of work on the barrel itself, because firing the gun will give you marks on that part (light ones) anyway, so got it just to where it was all silver there. On the breech block I used the glass in the kit, laid the sandpaper on it, and just worked at it until it wasn't doing anymore, then moved through the grits. Mine is a mirror surface all around the breech block now. No pics though, can't seem to get the digital to take good gun photos.
I polished my 1911 once (using 1500 grit sandpaper from Advance Auto Parts), but after about a week, I re-brushed the surface (Scotch-Brite pad works well for this). Polished steel seems to be real bad about picking up tiny nicks and scratches; every time I would lay my 1911 down, I would have to polish out a scratch that got on it. I also used to have a polished Vaquero that behaved the same way, but i got rid of it because I decided i didn't like shooting .44 magnum. Anyway, my point is you have to be really careful with polished steel. Chrome plating holds up better, but I doubt anyone wants to pay for that.
I armadillo'd mine after I got done polishing it. No issues with scratches (except on the part of the barrel that gets rubbed by the slide anyway) or nicks so far. Do a search for "hot armadillo" that's how I armadillo'd it since the stuff doesn't like sticking to the smooth glassy surface.
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