I have an older Colt that has a few rust spot but I don't want to refinish it. What's the best way to remove light rust spots? Also the stainless barrel has a few light spots that I tried using Flitz on but it didn't help.

I hear 000 steel wool works.

Use an old wheat penny, which are pure copper.  I works surprisingly well.

Don't use a new one which is zinc and will scratch it.  

Not sure I would use copper on stainless steel.  Try an old Nickle.  Nickle is soft, and at least it's the same color.

Fine steel wool and be real careful on a collector weapon.

Quoted: I have an older Colt that has a few rust spot but I don't want to refinish it. What's the best way to remove light rust spots? Also the stainless barrel has a few light spots that I tried using Flitz on but it didn't help.

If its just light surface rust, Soak the spots with Breakfree overnight or more if needed, most of the time the spots will just wipe off after that. If not I use very fine steel wool that has been sprayed with breakfree.

Electrolytic rust removal!  All you need is some water, wire, washing soda, a plastic dish pan and a battery charger!  (You don't need the digital clamp meter)



Welder lock before:


Welder lock after:


It converts rust into a powder that can be brushed away and has no effect on unrusted metal.  It's wondermous, I guarantee!

Edit:  By the way, the Vise Grips I'm using in the top picture to hold the work piece were themselves rusted beyond use just 45 minutes before that pic was taken.  Now, I use them regularly and you can barely tell they had been left outside next to a barn for several years.

Soak the rust for several hours or a day and try to rub it off with a cloth - old wash cloth, sock, soft denim, cleaning patches, and so on.

If that doesn't quite do the job, either stop and don't do anything else, or try lightly rubbing with 0000 steel wool and plenty of oil; that's about all you can do, except to protect the gun from additional damage.

I looked at a Winchester 1894 today, manufactured in 1906, that had blue remaining on the top of the rear sight spring and not a speck anywhere else on the gun, but it has a very light and scattered surface rust - this gun will look great after a clean up with steel wool, sort of a French gray color, and it's impossible to reduce it's value.

On the stainless gun, try rubbing the spots with a red pencil eraser.  Rub in the direction of the grain in the parts metal to hide the cleanup.

before you touch the steel wool, get a brass or bronze brush, a bore brush will do,
soak the area in oil, (breakfree, kroil, or whatever)
lightly scrub with the brush,
wipe
the entire area will turn the color of the brush, but will wipe off with a little elbow grease,
rust will be gone, and the finish around the rust will not be harmed,


ETA, do NOT use steel wool on stainless, the wool peices will "bond" with stailess and rust in a heart beat,,,

try a polishing wheel with some fine jewelers rouge if you have access to it