At a WAG, I would say the rings/crescents in the barrel were made by a steel rod...possibly a "field expedient" squib rod, or maybe even a storage device that held the pistol in position by means of the bore...(My own safe uses wooden dowels of various diameters and heights to hold and separate my pistols & revolvers)...
I'd conjecture someone used a cleaning rod and a hammer to dislodge an obstruction (like a squib load/bullet) in the barrel, as Ed Tinker suggested...
|