There was some mention of the shiny metal washers behind the drum where it threads into the barrel. This shiny metal most likely is "shim stock".. Shim material comes in sheets of various thickness. I have it in my shop in .005 in , .010 ,etc. Had a guy come in to the shop and complain his percussion drum was rotating loose. First thing I asked him , what do you do to clean the rifle?? He said he always unpinned the barrel from the stock , unscrewed the drum , and placed the breach end into a can of soapy hot water and pumped a rag on r/r back and forth in the bore. Asked him why he didn't just take out the #10 clean out screw in the end of the drum , remove the nipple and pour some hot water in the bore w/a funnel and just push it through and out the drum w/ the drum still attached in the barrel ? He simply said there wasn't anyone at the place where he purchased the new rifle to instruct him how to clean a percussion rifle ,and it seemed logical to use the leverage of the nipple to easily unscrew the drum for cleaning. I explained to him , that m/l barrels are cut from "lead bearing" steel alloy for easy machining. The steel is soft enough it will not stand continuous loosening , and tightening of the drum. The drum is made of a harder steel alloy and will eventually tear the threads out of the barrel..............So , the next half hour was spent educating the newbee how to care for his .36 squirrel rifle. Any way , back to the shiny washers mentioned above . The fix for a loose out of position drum is make washers out of shim stock and through trial and error , the drum will tighten in to the right position under the hammer nose. Hope all this will help some unknowing person with a loose drum to understand what's happened..............oldwood