straightshooter wrote:Many years ago in the 303 sporter era when corrosive primer ammunition was still commonplace you risked a rusted bore if you left it without any form of cleaning overnight.
The reason was that the corrosive primers contained potassium chlorate. Although it made for excellent priming characteristics it left a corrosive salt lining your barrel.
The water cleaning method at least got rid of the corrosive salt residue even though it did nothing to remove jacket fouling in the bore. A longer term issue with that metallic fouling was that it trapped some of the corrosive elements under the fouling leading to serious pitting in the longer term even if the barrel was well oiled.
An expedient nightly ritual was to have a small tin of boiling water with a drop or two of Young's 303 oil in it placed on your camp fire and have a well fitting patch on your cleaning rod. You would then put the muzzle of your rifle into the boiling water and draw up the water by pulling up the cleaning rod until the patch reached the chamber. At that point the patch would lose it's seal on the bore and the water would run back into the tin to continue boiling. You would continue doing this until the the barrel was quite hot.
Being hot the barrel would dry out very quickly and there would be a light film of oil left on the barrel sufficient to protect it for a few days but not enough to worry about patching out prior to shooting again.
The barrel of course would need proper solvent cleaning prior to oiling for longer term protection during storage.
In latter years this handed down knowledge seemed to get "dumbed down" in it's transmission to simply pouring hot water down the barrel through some kind of funnel.
The boiling water through the barrel achieves very little with modern truly non corrosive ammunition. At best it removes some of the combustion products that would have been better removed with a dry patch but without the mess and bother.
In fact, the boiling water though the funnel predates the 303 sporter era and was used by the miltitary since the MH days. Photo of armouers funnel and cup for cleaning BP and/or primer salt residue. Can be used with either MH or LE.