Dirty Barrel

[BradY]

My 22BR lilja 1:10 twist barrel wont stop spewing out black stuff. Ive cleaned it with an abrasive cleaner similar to JB paste, with upper engine cleaner and standard tetra solvent and each time I run a brush down and follow it with a patch of upper engine cleaner, it comes out filthy. All the cleaning gear is clean so it cant be that. Anyone have any suggestions? Its shooting fine, but I want to get the barrel producing white patches before getting it set back and rechambered again.

 

[Eddie Harren]

JB Bore paste always turns black, when used on stainless steel. Put some on a patch and rub the OUTSIDE of the barrel. Then check the patch. I always follow a JB scrubbing with a healthy dose of Kroil/TEC mix.

 

[BradY]

Yes the abrasive cleaner I use is called defoul and is made here in Aus, and yes it turns black when you work it in the bore. Trouble is that Ive done that already. This is just a run with a bronze brush followed by a wet patch with upper engine cleaner (the sort that is used to remove carbon from throttle bodies when cars are running) I have emailed Dan Lilja to see what he thinks, but Im starting to think that this may well be the base layer of build up before bare steel and probably needs to be there. There arent any build ups of carbon as of the last time it got a clean and borescope and its had 10 shots since then. Im going to give it a good oil and store it until the gunsmith is able to set back the barrel and rechamber to straight 22BR. From there its going to be a hunting barrel with 65gr sierra gamekings.

 

[rayjay]

Most of what you are seeing is minute particles rubbed off the tips of all those bristles on the bronze brush. Never judge bore cleanliness by the first patch after the brush.

 

[Bob3700]

The best method to validate your bbl cleaning technique is to borrow a borescope and view the bbl after you have cleaned.

Carbon fouling hides (and is hardest to clean) in the corners between the lands and grooves. That is where your challenge lies. Scope those areas out to see what is still trapped at that point.

Slip 2000 really attacks that carbon and gets under it so that the brushes can carry it away.

Bob