I have found that taking a "Chore Girl" copper pan scrubber, cutting a piece out and wrapping it around a bore brush works very well on removing lead fouling.

A method that I prefer is to use a small piece of "Lead-Away" as a patch. Sold under many names, Lead-Away is the yellow cloth impregnated with God-knows-what that one can buy at most gun stores, for removing lead from revolver cylinders, bullet-moulds, wherever it may accumulate on metal surfaces.

For gun bores, just cut a scant 1"-square patch from the cloth (for .30 caliber rifles), stick it on the spear point of your cleaning rod jag, and run it into your barrel. A few strokes back and forth and the yellow cloth will be coal black if there was lead in your barrel. And the lead will be gone...

Follow with a couple of wet, and then dry, patches to remove any remaining"Lead-Away". away