for really bad bore leading or when all else fails make a 50/50 mix of distilled vinegar and hydrogen peroxide. Degrease the bore with dawn dish soap. Stick a toothpick into the nipple or touch hole. Fill the bore with the acetate solution (it works faster hot) and let stand for a half hour, pour mixture out of the bore into a sealable container such as a cleaned out plastic quart engine oil bottle. Brush out and patch out the bore. If any lead remains repeat the process until clean. Most of the crud the brush and patch removes will be tin, antimony, and other trace metals that were alloyed in the lead and were left behind as dust when the lead dissolved. Rinse the barrel with water and oil it per your usual method. Save the used mixture as it can be used many times before becoming ineffective. The mixture becomes lead acetate as it dissolves the lead into the solution, therefore the used solution is now toxic and should be labeled accordingly. Do not leave the solution in the barrel for hours on end as it will eventually rust the bore. When the solution "wears out" pour it into a gallon jug and neutralize it with enough baking soda that it just stops fizzing and let it settle overnight. The lead will fall out of the solution in the form of a off white sludge (lead dioxide O2Pb, AKA white lead, and some sodium acetate). Most of the liquid can then be poured off down the drain as it is no longer toxic. The sludge and remaining water can be poured into an old dead car battery for recycling, or put in paint cans and eventually recycled when your locality hosts such an event. Don't let the stuff dry out as it is a rather combustible oxidizer in that form.
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