I snapped a nipple pick off in the flash hole of my Mossberg ML shotgun barrel. The breech plug is welded in and not removable. It sat on my bench for 2 years while I stared at it trying to figure out a solution. Didn't want to drill it out, bits that were strong enough were all too large compared to the flash hole. Took it to a machinest. He was afraid to tackle it. Then one day the light went on. I took it out to the garage, poured about 6" of Auto Transmission Fluid in the barrel, and seated a 7/16" wooden dowel in a plastic ML sabot. I stood it on a plank, pushed the sabot down until it touched the oil and rapped it with a 3 pound hammer. One swift blow drove the snapped off portion of the pick right out backward, hydraulically. My inspiration? A thread on a gun site (can't remember which one) about hydraulically decapping Berdan primers. RD