BTW-many of us have stopped using boiling water, or even very hot tap water when cleaning our rifles and smoothbores. The reason is the flash rusting that happens in some barrel steels due to the very rapid drying and heat which starts oxidation almost immediately upon drying.
; We use cold tap water only, then dry with patches, then spray WD40 into the muzzles until it runs out the vents(or nipple seats. A WD40 wet patch is then run hard into the bores to flush out the excess from the vent or nipple seat and blast out any remaining moisture from around the breech faces. The final thing to do, is to wipe down the outside of the barrel with a WD 40 wet patch and reassemble.
; I've been doing it this way since the late 70's and have not experienced any after rust, even when storing rifles for several years between uses. I live in an area with an average humidity of 50%, which is fairly dry compared to Eastern Canada, around the Great Lakes, especially.
; I think putting the breech of the barrel into a bucket of water and flushing water into and out of the bore under pressure paramount in getting the bore spottlessly clean.
; Cold water disolves BP fouling better than hot, by the way. Note in the instructions, hot water is used only to aide drying the bores. Today, we have water displacing lubricants that can remove any last vestage of moisture, so hot water is never needed and is actually to be avoided due to the accumulative effect of after-rusting causing pits over the years.