Barrel rust (inside of barrel)

7

762x39

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How does one deal with this? I've put some rounds down it, and thought they cleared it out, but after cleaning, it's still there. I'm guessing the gunk from shooting covered it up. It doesn't really look like it's to the point of pitting the steel, but I don't know for sure.

I can see rust from the muzzle end, and the chamber end, so I assume it's like that all the way through the barrel.

The barrel is a Colt 9mm AR barrel that my uncle found in his "spare parts bin" in his basement (see a couple posts down. I forgot to mention this was unfired before I got to it). So I threw together a 9mm build with it.

How should I deal with this? Put more rounds down the pipe? I've only got a few mags through it.

I've used foaming bore cleaner and CLP (with brass brush/jag/patches), and still no luck:confused:.
 
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My advice would be to keep shooting it. Later, when you clean it, run a patch soaked with gun oil through the barrel to keep the rust from getting worse.

I recently picked up an old Mosin with a rusty, pitted barrel. It still shoots 1.5moa! I'm afraid that if I aggressively scrub the barrel accuracy will get worse.
 
Yeah, I put a generously soaked patch down the barrel after I cleaned it.

But I want to get rid of it. I hope my only option isn't just stopping it from getting worse:(. I'll put some more rounds through it when I get a chance (this thing is fun as hell to shoot), but until then I'm open to as many suggestions as possible:D.

Thanks for the advice, Auto.
 
Hot water and soap

Try cleaning your barrel with hot water and soap or old WWII GI bore cleaner. Many countries have loaded 9mm using corrossive priming and I'm guessing that at one time your barrel had some run down it, so the corrossive salts have been embedded in the barrel.

me26245
 
I should have clarified this in the OP, sorry........The barrel, although sitting in a basement, collecting dust and starting to rust, was unfired before I installed it. My uncle got it new (back in 2000 or so) for a buddy of his, and never ended up giving it to him.
 
There is nothing you can do about replacing steel that was removed by rust. Its gone.

AR barrels are relatively easy to replace. So it if bothers you, replace it. Get on the web and find a barrel source.

Since your rifle is a 9mm, I really doubt that you will see much if any difference on paper. It is not like you are going to be making any 600 yard head shots with the thing.
 
Umm Are you sure its not copper fouling you are seeing, sometimes a thin layer of it embeds in the pores of the steel in the bore. It would look brown and would sort of look like a line on top of each of the lands at the muzzle end.

Just a thought.

In any event get some good 9mm ammo and shoot a couple hundred rounds and see if that erases it or it gets worse.
 
Umm Are you sure its not copper fouling you are seeing, sometimes a thin layer of it embeds in the pores of the steel in the bore. It would look brown and would sort of look like a line on top of each of the lands at the muzzle end.
Click to expand...

I don't think so. I cleaned it, and it didn't go away.

I'll just put some more rounds through it, and hopefully it helps.
 
The only way to get rust out if it's very heavy would be to lap the bore or if you're real adventurous you could run a patch with acid on it to take the rust off.
You'd have to be very careful as it would also remove bluing if you got it on something you didn't wish to strip........Ask me how I know. :rolleyes:
 
Not saying I would recommend doing this.. BUT-If I were in a position that I really wanted that rust out, and knowing that if I did not succeed in getting it out that I would purchase a new barrel anyway, I would use Muriatic acid. The same stuff that is used in swimming pools.

I would set up OUTSIDE your home, and with a bucket full of fresh, clean water to rinse myself off with, or my gun off with in case I spilled it. A water hose with a nozzle on the end would be even better. If you get this stuff on your skin, or accidentally splash it in your eyes, you will regret having attempted this!

Use rubber gloves, and safety glasses. Separate a small amount of Muriatic acid, say 1 ounce or so from the original container. Put the lid back on the original container, seal it tightly, and put the original container far away from your immediate work area.

Now, before you begin using the acid, get a spray bottle from in the house. Rinse it well to get out all traces of the original fluid out. Put at least 4 full table spoons of baking soda into the bottle-Arm & Hammer is fine-followed by maybe a quart of hot water. Put the spray nozzle back on, and shake bottle vigorously. This will be used to deactivate the acid in the barrel when you are done removing the rust from the barrel, and also to deactivate the acid on your cleaning rods, and anything else you get the acid on.

Now, using blue painters tape, tape up the outside of the barrel, all the way back to the stock to protect it from accidental acid exposure.

Fill the magazine area with paper towels to absorb any acid that drips, and to protect the rest of the action from acid exposure. Now, using your regular cleaning supplies, dip a patch in the acid, and then run it through the bore. Let it sit for about 5 minutes to really work, then immediately spray down the barrel with the spray to deactivate the acid. I would put a napkin in the end of the barrel, stand the rifle on the barrel and keep spraying into the breech until the napkin is wet. Then, with a fresh patch sprayed with the same deactivator, and having sprayed the length of your cleaning rod with deactivator-scrub the barrel thoroughly. Do this TWICE. Then clean with your usual solvent. Then inspect the barrel to see how much rust, if any, remains. If you still have rust, do the process again. Don't leave the acid in the barrel any longer than necessary as it will dissolve the steel in the barrel, along with the rust.

This would be a LAST resort type fix, but I guarantee you it will remove all rust from the barrel with a quickness. You will have a shiny, if not pitted, bore when this is done.
 
Mini 30 light bore rust removal success

To remove light rust from a Ruger Mini 30 stainless barrel bore I did the following
1. Cleaned barrel then de-greased with isopropyl alcohol
2. Cut a Scotch Brite red pad strip to fit into jag, about 3" long
3. Ran jag up and down barrel with short twisting strokes until pad was worn and very black
4. Repeated step 2 & 3 until rust was gone, took 5 times
5. Cleaned bore and chamber to remove Scotch Brite fragments w de greaser
6. Polished bore w Brasso
7. Degreased bore
8. Applied light coat of oil to bore

How rust formed is a mystery as I always carefully clean after firing and apply oil to bore afterwards
 
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