The only guns I get much lead buildup around the forcing cone are my 22 revolvers. In other calibers I shoot mostly plated or jacketed bullets. So to clean the lead off the frame on the 22's I use a scraper tool I made by hammering flat the end of a 556 shell. Scrapes the lead right off and can't harm my Stainless Steel revolvers. Also I suggest shooting different bullets that won't lead your gun.

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Accuracy supercedes Speed