Several questions about rust in my Mosin bore..

[Caedo]

First off, I'm sorry if this is in the wrong forum. I conducted a search to try and find an answer to my question and I did outside research, but I still haven't found really credible or consistent/reliable information, so, here I am.

I recently bought a Mosin Nagant 91/30, and when I got it the bore was in immaculate condition. Full of cosmoline of course, but that was easily cleaned out. I shot corrosive Russian surplus ammunition out of it when I first fired it, and, having found what seemed to be reliable information regarding the cleaning process of corrosive ammunition, I was given the impression that Hoppes #9 was all that was necessary to properly clean the corrosive salts out of the bore. O

Well, that was quickly proven wrong and rust formed in a hurry. Even with oil in the bore. I cleaned it out, thoroughly with hot water (further research after the first rusting led me to this) and I left oil in the bore again. However, rust formed AGAIN, this time in tiny isolated patches. I've taken it to the range two times after the first time I shot it, and the rust keeps coming back.

I've tried boiling hot water, Hoppes #9, Break Free, and a bore brush but nothing stops it. I leave oil in the bore (Hoppes Elite gun oil) and I leave the bolt out of the rifle when stored. It's stored in a cool, dry room.

My questions: how can I stop this demon rust, and what kind of damage and/or side affects come from rust of this nature?

 

[tyeo098]

Hoppes IS all you need. It says so on the bottle.

Did you run an oil patch through afterwards?

EDIT: you said you did... hm thats odd.

I live in groggy humid Florida and I have no problems with rust.

 

[P5 Guy]

Is it Rust?

Or is it copper fouling?
Try a strong copper solvent such as Sweet's 7.62. Follow the instructions this stuff is strong and smelly. The patches will come out with blue/green stains, that's the copper.

 

[30cal_Fun]

I use Balistol on my mosin nagant. After shooting, I spray the barrel liberally with it. when I get home I clean as usual, Balistol works like WD40, break free, gun lube and even romoves rust and copper fowling a bit. Never had any rust. I don't use anything else anymore.
There is a reason it has been in use for more than 100 years and two world wars.

 

[Clark]

I was trying for years to get a 1" group until 2002, and visiting ranges in humid Western WA.
Everyone said they got 1" groups, but I only saw 2 guys that could do it on the target.

One was a guy at Isaquah with a 223 Win 70 Coyote, a competition benchrest and V bag, and Federal Gold match ammo.

Another guy at Puyallup with a 91/30, had a bore that looked like a sewer pipe.
He had put Outers foul out electrolysis in the bore and got Copper out for a while and then rust. He poured a Lead lapp and embedded valve grinding compound, and made a bore guide with a brass cartridge case. He found and tight spot in the bore and lapped it out. After he shoots a couple small groups, the groups open up, and he needs to use the Foul out process again. He uses Norma brass and 180 gr Sierra bullets with IMR4350 and very hot loads. He is 60, has been hunting with a 91/30 since he was 14, and still shoots a deer every year with a 91/30.


I recently sporterized an 91/59 for a young man.
I took it to the range, a long with my 91/30 and my M39.

My rifles shot 2 moa.
His shot 10 moa.

I warned him we should not waste time with a rotten bore.
I guess I will have to re barrel it for him.

 

[pdawg.shooter]

You want to clean and polish that bore shoot 50 or so paper patched lead bullets through it. If it is real bad a little 600 grit lapping on the first 3 or bullets will save time.

 

[brickeyee]

To remove ALL the chlorate (corrosive) primer residue you need to degrease the bore completely, then use water and a surfactant (like in Windex) to dissolve the corrosive salt.

Use HOT (almost boiling) water, THEN oil the bore thoroughly.

Once you put oil in there you made it much harder to dissolve the corrosive salts.
The oil keeps water from getting to them, but does nothing to prevent them from attacking the steel.

The salts are corrosive on their own, but are also hygroscopic.
They attract moisture from the air and then cause rusting and corrosion damage.

 

[Caedo]

I really appreciate the prompt and numerous, as well as helpful responses. You've all given me a lot of information. However, I do need to know.. what kind of degreaser is safe to use in the bore? I've heard of people using things like brake cleaner or things like this, but I've also heard that they are harmful to the metal and that they are generally not safe to use, so I don't know.

 

[Gik-tal]

I have used a mix of warm water and dawn dish soap to remove corrosive residue for years, never had a problem. Use the mixture just like a bore cleaner, after you run a few dripping wet patches thru the barrel to fush out any of the salts left behind, run a few dry patches thru and then clean like normal with the Hoppes #9, then run a few patches with Kroil Oil thru the bore to remove the moisture. If the barrel is already rusted you may have to clean it out with something like Montana Extreme bore paste, to more or less sand out the bore.

 

[Frozen North]

My mosin 91-30 was so dirty, it took several hours of intense cleaning to even make a dent in it. It was loaded with black crud, cosmo, and especially COPPER. I used gun scrubber to start, then switched to degreaser and hot water. After that, I put Butch's Bore Shine through it till the blue was gone. It was still gunky!!!

Anyhow, you may have enough junk in there for the corrosive salts to hide in yet. Really get the elbow grease out! Hot water and a product called greased lightning worked well.

As stated above.... could it be copper you are seeing?

 

[30cal_Fun]

I tried the hot water thing and other methods many times after shooting corrosive ammo, but since I switched to Balistol years ago, I don't use anything else.
Balistol is the only thing you need, that might sound a bit over enthousiastic, but in Europe, everyone uses it and has so for over a hundred years.

Frozen North has a good point, if your barrel is still full of copper fowling and powder residue that hasn't been cleaned out, corrosive salts can hide in it.
I never had this happen to me trough, and my bore looks like a train wreck; it is dark as night. (still strong rifling though).
Mosin Nagants are notorious for having barrels that take hours, even days to clean up well, a lot of Mosin bores will stay dark no matter how much you clean them (like mine).
Once in a while I use Shooters Choise to get the remaining copper fowling out. But other than that: Balistol, just spray the barrel when finished at the range and clean well (bronze brush, patches, etc.) at home.

 

[kingcheese]

spray your bore with windex, when done shooting, after that i like to use the winchester solvents made for shotguns, the key to getting rust and copper out is to let the bore soak with the cleaner on it, spray your barrle, let it soak for about half an hour, dry it out with a few patches, then brush, then solvent, then wait, and just do that over and over again, maybe 4-5 times and it will all come out

 

[Clark]

10 years ago I still shot surplus corrosive 8mm and 7 .62x54R ammo.
At the range, before I left, I would put a tuna can on the ground and fill it with Ammonia.
I would pull the bolt out of the rifle and put the muzzle in the can.
I would put a patch in a loop on the end of a cleaning rod down the bore.
When I pulled up the rod, the suction would draw Ammonia all the way up to the chamber.
When the patch got back up to the chamber, the suction would break and the Ammonia ran back down into the can.

This did stop the corrosive ammo from wrecking the bore.
But it did take the bluing off the muzzle.

 

[Caedo]

I'd like to thank everyone who replied. I followed everyone's advice about using hot soapy water, as well as Windex, and I've had no rust since. I discovered that there was indeed also a lot of fouling that looked like rust, which also came out. I was relieved to find the lands and grooves intact with no pitting.