DocRock
member
It seemed worth creating a separate thread on this issue. Since there seem to be members who believe advertising copy rather than scientific analysis and therefore think that black powder substitutes, or at least their favorite brand, are thereof non-corrosive or "less" corrosive than either black powder itself, or other substitutes, it seemed wise to set things straight. That is not true.
All black powder and all of its known substitutes marketed as such in the US are hygroscopic and corrosive.
Black powder substitutes are not made because they are "less" corrosive. They are not indeed made for the increased convenience of the user at all. They exist because black powder is regulated as an explosive, requiring increased administrative, storage, handling, and transportation costs and burden. Black powder substitutes exist to circumvent regulation as an explosive.
Hygroscopic means a propensity to attract and retain moisture:
https://www.sciencedaily.com/terms/hygroscopy.htm
Black powder (BP) and its substitutes (BPS) all leave desiccated solid residue as a result of combustion in the firearm. This residue is itself hygroscopic. It will attract and retain moisture.
In addition to the hygroscopic nature of burnt residue (fouling), both BP and BPS, when combusted, produce hygroscopic, corrosive salts. In the case of BP, the main such salt is potassium nitrite (a by-product of potassium nitrate in BP). In the case of all BPS currently marketed as such in the US, the corrosive salt is called potassium chloride. Potassium chloride is a by product of the combustion of potassium chlorate or potassium perchlorate, a substance found in all BPS marketed as such in the US, and the principle corrosive agent in "corrosive primers". Potassium chloride is the main substitute for sodium chloride, aka "table salt".
Therefore, all black powder AND its substitutes are hygroscopic and corrosive.
Gas spectrum analyses of black powder and black powder substitutes demonstrating that the latter all contain potassium perchlorate:
National Institute of Technology & Standards: Forensic analysis and differentiation of black powder and black pow-der substitute chemical signatures by infrared thermal desorption –DART-MS
https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=926574
Rapid Communications in Mass Spectometry (2010;24: 1377–1386) Analysis of ascorbic acid based black powder substitutes by high-performance liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry
https://onlinelibrary.wiley.com/doi/pdf/10.1002/rcm.4520
Potassium chloride (BPS residue) is at least as hygroscopic as potassium nitrite (BP residue)
Nature (2017):
Hygroscopic properties of potassium chloride and its internal mixtures with organic compounds relevant to biomass burning aerosol particles
https://www.nature.com/articles/srep43572
There is no easily retrievable data establishing the hygroscopicity of potassium nitrite, the salt residue of potassium nitrate. However, that does not mean that potassium nitrite is less hygroscopic than potassium chloride.
There can be no argument that failing to clean a firearm in a timely manner that has fired BP will yield rust and that the greater the degree of humidity to which the fouling is exposed and the longer that exposure, the more it will rust. The same is true for BPS. And, there is reason to believe that the effect of exposure of potassium chloride to steel is deep pitting as opposed to the surface rust of potassium nitrite:
https://www.camp22.org/black-powder-pages/barrel-fouling-black-powder-vs-substitutes
Potassium chlorate/perchlorate is the principle corrosive agent in ammunition with "corrosive primers" and both leave potassium chloride salts in the rifle after shooting. Is there anyone who would suggest not immediately cleaning a rifle after shooting ammunition with corrosive primers?
https://blog.cheaperthandirt.com/corrosive-ammunition/
Happily, removing the corrosive salts of BP and BPS are the same, and quite easy. Water. Just as those shooting "corrosive ammunition" are encourage to wash out the barrel with hot water, so too, copious amounts of hot water will remove the corrosive salt residue of BP and BPS. I, for one, prefer a little dish soap as well, but according to the science, it is not strictly necessary. Aqueous solvents may also work. Non-aqueous, petroleum product based solvents may not and are not to be recommended on their own.
All black powder and all of its known substitutes marketed as such in the US are hygroscopic and corrosive.
Black powder substitutes are not made because they are "less" corrosive. They are not indeed made for the increased convenience of the user at all. They exist because black powder is regulated as an explosive, requiring increased administrative, storage, handling, and transportation costs and burden. Black powder substitutes exist to circumvent regulation as an explosive.
Hygroscopic means a propensity to attract and retain moisture:
https://www.sciencedaily.com/terms/hygroscopy.htm
Black powder (BP) and its substitutes (BPS) all leave desiccated solid residue as a result of combustion in the firearm. This residue is itself hygroscopic. It will attract and retain moisture.
In addition to the hygroscopic nature of burnt residue (fouling), both BP and BPS, when combusted, produce hygroscopic, corrosive salts. In the case of BP, the main such salt is potassium nitrite (a by-product of potassium nitrate in BP). In the case of all BPS currently marketed as such in the US, the corrosive salt is called potassium chloride. Potassium chloride is a by product of the combustion of potassium chlorate or potassium perchlorate, a substance found in all BPS marketed as such in the US, and the principle corrosive agent in "corrosive primers". Potassium chloride is the main substitute for sodium chloride, aka "table salt".
Therefore, all black powder AND its substitutes are hygroscopic and corrosive.
Gas spectrum analyses of black powder and black powder substitutes demonstrating that the latter all contain potassium perchlorate:
National Institute of Technology & Standards: Forensic analysis and differentiation of black powder and black pow-der substitute chemical signatures by infrared thermal desorption –DART-MS
https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=926574
Rapid Communications in Mass Spectometry (2010;24: 1377–1386) Analysis of ascorbic acid based black powder substitutes by high-performance liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry
https://onlinelibrary.wiley.com/doi/pdf/10.1002/rcm.4520
Potassium chloride (BPS residue) is at least as hygroscopic as potassium nitrite (BP residue)
Nature (2017):
Hygroscopic properties of potassium chloride and its internal mixtures with organic compounds relevant to biomass burning aerosol particles
https://www.nature.com/articles/srep43572
There is no easily retrievable data establishing the hygroscopicity of potassium nitrite, the salt residue of potassium nitrate. However, that does not mean that potassium nitrite is less hygroscopic than potassium chloride.
There can be no argument that failing to clean a firearm in a timely manner that has fired BP will yield rust and that the greater the degree of humidity to which the fouling is exposed and the longer that exposure, the more it will rust. The same is true for BPS. And, there is reason to believe that the effect of exposure of potassium chloride to steel is deep pitting as opposed to the surface rust of potassium nitrite:
https://www.camp22.org/black-powder-pages/barrel-fouling-black-powder-vs-substitutes
Potassium chlorate/perchlorate is the principle corrosive agent in ammunition with "corrosive primers" and both leave potassium chloride salts in the rifle after shooting. Is there anyone who would suggest not immediately cleaning a rifle after shooting ammunition with corrosive primers?
https://blog.cheaperthandirt.com/corrosive-ammunition/
Happily, removing the corrosive salts of BP and BPS are the same, and quite easy. Water. Just as those shooting "corrosive ammunition" are encourage to wash out the barrel with hot water, so too, copious amounts of hot water will remove the corrosive salt residue of BP and BPS. I, for one, prefer a little dish soap as well, but according to the science, it is not strictly necessary. Aqueous solvents may also work. Non-aqueous, petroleum product based solvents may not and are not to be recommended on their own.
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