There's no question that a borescope is the best way to look because the color difference between lead and steel is apparent. But in my case the lead was not distributed throughout the whole barrel, but rather was partial and not entirely even, favoring mostly the breech end but with patches of it further down the tube. As a result, the brush roughed up the shiny lead to make it appear as dull patches, while the bare steel remained glossy looking. It was the contrast between the dull and the shiny areas that stood out sighting down the tube.
The gun was my Dan Wesson 15-2. That let me take the barrel off and use one of those 90° Lucite bore lights with which I could see enough to pick out the color difference between the lead at the breech and the steel at the muzzle without getting inside.
has been around since Ed Harris first came up with it in 1991. If you apply it at the range while the fouling is still hot and then let it stay in the gun for the drive home, you'll discover it does a much better job on carbon than if you let the carbon cool and harden first. Board member Hummer90 has even gone to the extreme of decapping rifle cases immediately after firing so that he could use a cotton swab to put some in the primer pockets before they cooled. Same reason: to prevent carbon hardening. On another forum he has an interesting theory about the contribution of hard carbon particles to throat wear
as they're shot down the bore.
These days I use Boretech Eliminator
. It cost more but works faster and attacks and removes copper quickly, which Ed's Red does not. It also attacks tin and/or antimony in cast bullet alloy (I can't tell which; I can just tell that it etches the surface of a cast bullet left sitting in it overnight), which Ed's does not. It's also one of the few virtually odorless cleaners out there, which keeps SWMBO from complaining. I also apply it at the range while the gun's still warm using a pump spray and letting it wet the whole bore. I still keep a gallon of Ed's Red in a covered stainless container, though. I use that as a soaking cleaner for stripped-down guns and gun parts. Over a period of a week or so it flows powder fouling off the metal sitting in it.