Chemistry:Black powder substitute
A black powder substitute or gunpowder substitute is a replacement for black powder (gunpowder) used in muzzleloading and cartridge firearms. Black powder substitutes have slightly different properties from gunpowder and are subject to different restrictions. Compared to gunpowder, black powder substitutes may have reduced sensitivity as an explosive, increased efficiency as a propellant powder, different density, and/or reduced ignition efficiency.
Types
Hodgdon's Pyrodex was the first widely available substitute for black powder. Pyrodex is less sensitive to ignition than black powder and uses the same shipping and storage guidelines as smokeless powder. Pyrodex is more energetic per unit of mass than black powder, but it is less dense so it can often be substituted at a 1:1 ratio by volume for black powder in many applications.[1] Pyrodex is similar in composition to black powder but incorporates several other compounds. The composition of Pyrodex, according to US Patent No. 4128443, filed by the inventor Dan Pawlak in 1975, is as follows (in % by weight):[2][3]
- 45% potassium nitrate
- 9% charcoal
- 6% sulfur
- 19% potassium perchlorate
- 11% sodium benzoate
- 6% dicyandiamide
- 4% dextrin
- 1% water
Its combustion is slower and produces a lower maximum pressure than black powder, and is often used for shooting historical weapons but provides the same amount of work.[4] Pyrodex produces higher projectile velocities than are commonly achieved with black powder.[5] Originally available as loose powder in two granularities, RS (Rifle/Shotgun) equal to FFG black powder and P (Pistol) equal to FFFg black powder. Pyrodex is now becoming available in select and solid pellet varieties. While Pyrodex offers improved safety and increased efficiency (in terms of shots per pound of powder) over black powder, the level of fouling is similar as Pyrodex is caustic and corrosive. Therefore, the same cleaning lay regimen used on black powder fouling must be employed when Pyrodex has been used.
Hodgdon also makes Triple Seven, one of the family of sulfur free black powder substitutes. It also contains potassium perchlorate but also 3-Nitrobenzoic acid. Triple Seven and Black Mag3 are more energetic by mass than black powder and can produce higher velocities and pressures. Triple Seven is a volumetric substitute for black powder but produces higher velocity. To match the velocities of a traditional black powder load, it is recommended to reduce the load by 15%.[6] Still burning carbon, the carbon-based fuel burned here is from the sugar family, not from charcoal.
Western Powders Company introduced Blackhorn 209 in 2008. It is made to be a volumetric substitute for black powder. Blackhorn 209 is non-corrosive, low-fouling, very consistent in gas generation, but non-hygroscopic.[7] It is dispensed in "black powder measures" for muzzleloading applications.
Measurement
The grain is the traditional measurement of the weight of bullets, black powder and smokeless powder in English-speaking countries. It is the unit measured by the scales used in handloading; commonly, bullets are measured in increments of one grain, gunpowder in increments of 0.1 grains.[8] There are 7,000 grains in one pound.
Black powder substitutes, are formulated to be a volume-for-volume equivalent of black powder, not an equivalent mass-for-mass (weight-for-weight). Black powder substitutes are measured by volumetric measurement techniques, not in grains on a scale, due to the difference in density compared to black powder. For example, to measure a "60 grain equivalent" of black powder substitute suitable for use in a muzzleloader rifle, one uses a volumetric measure that produces a volume of black powder equivalent equal to the volume of a mass of 60 grains of black powder. For example, because Pyrodex, a common black powder substitute, is less dense than black powder, a measurement by weight on a scale of 60 grains of mass of Pyrodex would be near a 30 percent overload.
Volume equivalence is a benefit in loading muzzleloading firearms, traditionally loaded using volumetric measures. This becomes an issue when fabricating black-powder cartridges through handloading using a black-powder substitute in place of black powder, since it is common practice to measure by weight when loading cartridges (there are published conversion tables).
Disadvantages
With the increased safety of the black powder substitutes often comes a reduced sensitivity to ignition. Flintlocks in particular need very sensitive, finely granulated powder for use in the flash pan, and black powder tends to perform more reliably in these and traditional caplock guns than substitutes. Modern in-line muzzleloaders provide a stronger ignition than traditional designs and this helps to increase reliability with less flame-sensitive substitutes. In addition, magnum percussion caps are often recommended for use with black powder substitutes for both inline and traditional caplock guns, in place of the #11 percussion caps traditionally used with black powder in these guns, to achieve the best ignition reliability.
When used for recovery system ejection charges in high-power rocketry, black powder substitutes need a greater degree of confinement to ensure a complete burn and generation of sufficient ejection pressure. This can be achieved by wrapping 2–3 layers of electrical tape over the ejection charge canister before installation.[citation needed]
Legality
United States
Black powder substitutes can be transported and stored in interstate commerce in the United States using the smokeless powder regulations instead of the more restrictive black powder regulations. As a result, black powder substitutes are becoming more commonly available than traditional black powder.
United Kingdom
Unlike black powder, Pyrodex does not require a license to buy or store in the United Kingdom, and an RCA (recipient competent authority) document is not needed.[9][10]
Citations
- ↑ Fadala, Sam (2006). The Complete Blackpowder Handbook (5th ed.). Gun Digest Books. p. 203. ISBN 978-0-89689-390-0. "Second, Pyrodex provides more shots per pound than blackpowder because it is less dense."
- ↑ J Forensic Sci, 2011 Jan;56(1):194-9."Discriminating Hodgdon Pyrodex(®) and Triple Seven(®) using gas chromatography-mass spectrometry" doi:10.1111/j.1556-4029.2010.01534.x
- ↑ D.E.Pawlak,M.Levenson, Deflagrating Propellant Compositions, US-Patent 4,128,443,USA,1978.
- ↑ Koch, Ernst-Christian (2021). High Explosives, Propellants, Pyrotechnics. Berlin: De Gruyter. pp. 578-579. ISBN 978-3-11-066052-4.
- ↑ Barnes Bullets tests on their projectiles using Pyrodex,Hodgdon's Triple Se7en and black powder https://www.barnesbullets.com/wp-content/uploads/2021/05/Muzzleloader-Data.pdf
- ↑ "Hodgdon Loading Notes Pyrodex and 777". http://pyrodex.com/loading.html.
- ↑ "BLACKHORN 209 RAISES THE BAR ON MUZZLELOADING PROPELLANTS". Chuck Hawks. http://www.chuckhawks.com/blackhorn209_press_release.htm.
- ↑ "International Practical Shooting Confederation". IPSC Canada. January 4, 2004. Archived from the original on 2007-07-09. https://web.archive.org/web/20070709162948/http://www.ipsc-canada.org/exempt04.pdf. Retrieved 2007-11-30.
- ↑ "Pyrodex propellant powder". http://www.marplerifleandpistolclub.org.uk/pictures/pyrodex1.htm.
- ↑ "Transfer of explosives". https://www.hse.gov.uk/explosives/transfer-of-explosives.htm.
- Pyrodex MSDS Material safety data sheet
- Triple Seven MSDS
External links
- rec.guns FAQ on black powder and substitutes
- BLACK POWDER, PYRODEX, AND THE NEW LOW-RESIDUE POWDERS
- What is the Difference between Black, Pyrodex, Triple Seven, and Smokeless Powders? by Randy Wakeman (2004).
- Goex powders—current black powder and black powder substitute products
- Pyrodex Tests—Information and comparative tests of various BP substitutes in high-power rocketry ejection systems
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