TassieTiger wrote:Heard a theory / urban legend RE cleaning centrefire. A cold barrel can’t be cleaned as efficiently as a hot barrel (metal expansion when hot - traps copper etc), therefore always shoot a couple bullets and start cleaning ASAP afterwards? Metallurgy ppl ? False? True?
straightshooter wrote:OMG
This is just (what once was) schoolboy chemistry!
Bore cleaning with the correct solvents is a chemical reaction and just about all chemical reactions are temperature dependant, that is the rate of reaction increases with temperature. Now in a rifle barrel you don't want the barrel too hot as this will drive off the aromatic solvent carriers in the bore cleaner too quickly thus rendering the overall process less reactive and effective.
This does not apply to internet fantasy cleaners like 'Ed's red' and similar which don't contain anything that can react with copper or lead.
This kind of belief in magic and lack of understanding is what happens when schools replace maths, physics and chemistry studies with gender studies and 'cargo cult' like thinking.
TassieTiger wrote:I’m not a metallurgist but I’ve seen steel grow from heat, I’ve seen molecules open up and lengthen...if you think of some of the tolerances involved in mech, rifling, etc - id not be surprised to learn that there is a much deeper cleansing potential from a hot barrel..
Strikey wrote:Also the boiling water down the barrel was used to remove the residue from the mercuric primers that were common in the early days of centrefire cartridges
bladeracer wrote:Strikey wrote:Also the boiling water down the barrel was used to remove the residue from the mercuric primers that were common in the early days of centrefire cartridges
Boiling water was also used simply because it was cheap and available.
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.
TassieTiger wrote:Worth asking the question just for info / pics of jugs.
Cheers.