Iam cleaning a 300 ulta mag. I have been using barns cr10, also shooting tsx's.. Thought i was doing a good job but after a good cr10 cleaning I put the outers foul out to work on it. That was 2 days ago. The last two times I pulled the rod it was covered on black gunk.I have never had one do this. Any one run into this?

no, but you'll need to give a little bit more detail on your procedure, i.e., what was the last thing you did 2 days ago and how did the patches look, etc.

dm

I shot 20 rounds tsx ammo. Then cleaned with cr10 until patches came out clean. I then oiled the barrel with croil and let nit sit overnite. First patch out was a little brown with flecks of copper. I then degreased the barrel and put the foul out copper remover in it. Several times pulled the rod out and cleaned the copper off. I changed the solution several times. The last two times i pulled the rod to clean it it was was coated with black. My thought was this was powder residue. I then cleaned with cr10 again and had about 10 cr10 patches in a row come out black. It then started turning patches light blue. I have oiled the bore and stopped for the night. Hope this help explane.

What is probably happening is you are cleaning off a few layers of overall fouling at a time.

Every time you shoot, you lead with copper fouling via bullet, and then a "powder/carbon" layer follows.

Ultimately it's like priming a wall, then painting it over and over.

Kroil does a good job when left sitting in a bore of loosening this stuff up. When your original patches came clean, you had probably reached a layer of fouling that was packed hard. After a few hours of saturation, it loosened up, hence, the black pwdr fouling again.

Sounds like you just have a bit more scrubbing to do to get it all out. My opinion is that just because a patch comes out "clean" doesn't mean diddly squat. I learned that after I started using a bore scope.

The best cleaners will leave copper/powder fouling if not left to soak awhile.

I'd take a wet pach with CR10, soak the bore good and wet. Let sit for several hours, then run a bronze brush about 50 passes, i.e., scrub the bore very well.

Run 2 more wet patches, then 2 dry patches.

Resoak in protective oil and check once more in 2 more days.

Is this a factory barrel? How many total rounds has it had and what has been your cleaning routine?

I used to use Shooters Choice religiously mixed with kroil. I learned that even though my patches were clean as new when I was finished, it wasn't doing a good job at all in the first 3-5 inches from the chamber.

A borescope is the ONLY way to tell if you are truly cleaning your bore, IMO.

Tjay,
I worked a lot with the Outers Foul Out machine. Ruined one barrel (.270 Win) while I left the solution overnight one time. The next morning I found a black-brown solution and a darkbrown rod. I fired about 1800 rounds and cleaned very regularly.
After this overnight soaking my groups widened from .75 MOA to 2,5! I sent my rifle to SAKO and they told me my barrel had corroded by the procedure and they advised to install a new one. As I did, with all the load development afterwards! But accuracy was restored, fortunately.
So, taak good care of your solution and control it in the beginning every 30 minutes, than after one hour, than two hours and refresh if the solution turns white. Do not extend the procedure any longer than five to six hours.
Relieve your procedure with alternative cleanings and start again with Foul Out, eventually.
Nice day,
J.

Thanks Doc and Jan. Doc, That is what i thought was happening and you confirmed it. Jan, Good info to know about the outers foul out.
Thanks again
TJAY

Doc;
Yes this is a factory 700 Rem barrel. I checked my records and I have fired 221 rounds through it. As a note, The last 4 rounds I fired before this cleaning adventure went into 3.6 inches at 300 yards. Thanks again