It's all for looks........a half-assed attempt to make it look like an early chromed carrier.
I saw one done a few months ago, thought it looked good, so bit the bullet and dove in.
Here's how I did it.....
1. Take a few days and convince yourself you NEED to do this because it's friggen kewl....
2. Grab some rust & blue remover, some various grits of wet/dry paper, and a dremel with a polishing wheel and some rouge or polishing compound.
3. Pick how much of the carrier you want to strip. If you take out the recoil spring, and set the dust cover in place, slide the carrier back and forth-it'll give you an idea of how much is visible when assembled. I did just the top of the carrier from the grooves up.
4. Grab a Q-tip and the rust& blue remover and go to town. Just be careful not to get it on stuff you don't want stripped...it works fast! Wear gloves too, that stuff is nasty. Once you let it do it's job, go over it with some steel wool to help get all of the bluing off. After this you're ready to sand.
5. I used 150, 220, 300, and 400 grit in sequence useing WD-40 as a lube to knock down the rough spots......it really doesn't take that long, and helps immensely whith the next step.
6. Grab the dremel and go to town, when you get the shine you want, clean it up and put a light coat of oil on it, reassemble and you're done! Easy......