Block the bore from the muzzle end with a cleaning rod and a greased patch just forward of the obstruction. Pour molten Cerrosafe into the chamber end. When the Cerrosafe solidifies, it will shrink very slightly. Use the cleaning rod to punch out the casting. The obstruction should come out with it. Re-melt the Cerrosafe, skim off the trash, and save the Cerrosafe for next time.
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