The Problems of Black Powder
A problem associated with black powder is its hygroscopicity. Black powder absorbs about 1.5 weight percent moisture under 75 percent relative humidity at a temperature of 21.1.degrees C. (70.degrees F.) over a period of 24 hours. If black powder picks up sufficient moisture, there is a possibility that the black powder will not burn as fast. High relative humidity may cause erratic behavior. Water may cause the potassium nitrate to migrate out of the black powder and cause corrosion of metallic parts.
Safety is a major concern during black powder production; see all the recent Goex plant explosions, and "Hatcher's Notebook" for more information. Black powder combustion generates significant amounts of carbon monoxide, sulfur dioxide and hydrogen sulfide. At flame temperature, potassium sulfide is produced in the liquid state and is likely to undergo after-burning with atmospheric oxygen to produce copious amounts of sulfur dioxide. The carbon monoxide and hydrogen sulfide are also susceptible to after-burning, yielding carbon dioxide and sulfur dioxide.
Sulfur dioxide is extremely destructive to tissue of the mucous membranes and upper respiratory tract, eyes and skin. Inhalation may result in spasm, inflammation and edema of the larynx and bronchi, chemical pneumonitis and pulmonary edema. Thus, exposure to sulfur dioxide can lead to a series of health problems and, in the case of extended exposure, death.
Consistency and reproducibility are known problems with black powder. The charcoal constituent of black powder imparts a degree of unpredictability to the performance of the igniter composition. Charcoal is produced by carbonization of wood. The chemical and physical properties of wood vary greatly, depending upon the particular properties of the tree species, soil composition and environmental conditions from which the wood is taken. Due to inherent variability of wood and fluctuations in the carbonization process, the properties of charcoal tend to vary from batch to batch. These variations can affect the consistency of black powder performance.
Weber's 1991 patent No. 5,320,691, assigned to the USA by the Secretary of the Army, further defines known issues with blackpowder: "Black powder is a low explosive composition of potassium nitrate or sodium nitrate, charcoal and sulfur.
Black powder is unpredictable in a sense that it can ignite unexpectedly and thereby cause property destruction, injuries, and death. The unpredictability of black powder originates from the variability of the charcoal constituent, which makes up 15% of the black powder composition. Charcoal is produced by carbonization of wood, a natural product that has physical and chemical properties depending on the tree species, soil composition, and environmental conditions. Due to the inherent variability of wood and fluctuations in the carbonization process, the properties of charcoal, such as its composition, ash content, pore structure, density and percent volatiles, vary from batch to batch and cause variations in the black powder performance."
This illuminates the continuing need in the pyrotechnic and small arms industry for black powder substitutes which are safer to produce, are more predictable and which are less hygroscopic than black powder. This information is well documented by Gary Chen and associates for Morton-Thiokol, and their efforts to replace blackpowder with "MRBPS" (Moisture Resistant Blackpowder Substitute), among many, many other sources.
With all these well-known, established problems, you might be wondering why black powder still exists? The hygroscopicity in an unfired state is proven; the residue is even worse both in its ability to attract moisture and its corrosivity. Considered an explosive, not only is it dangerous to manufacture, but difficult to ship and store as mandated by DOT regulations, and local availability can be problematic.
Blackpowder's easy ignition is the reason it is not easily replicated. Blackpowder has a very fragile grain structure, and its low-temperature ignitability is still desirable for military applications, some mining applications, and highway department use-notably pre-emptive avalanche work.
Smokeless powder was created as a black powder substitute; nothing could be more obvious. As documented by the US Army, FBI, BATF, and so forth, that is exactly what it was designed for. Anyone can buy a box of .45-70 Government cartridges and verify that. Moreover, most any box of shotshells you might happen across calls out "drams equivalent" right on the box; grams equivalent of blackpowder is what is being referred to. Over a hundred years ago, it was determined that 3 drams of blackpowder pushing a 1-1/8 oz. of lead in a 12 gauge equated to 1200 fps. A "three dr. equiv." 1-1/8 oz. 12 ga. load today through a relatively thin shotgun barrel has been standard fare ever since; there is no call to go back to black powder for all the obvious reasons.
With all the black powder negatives for small arms use today, you might wonder why it persists today? The short answer is that well-produced blackpowder, such as "Swiss," is difficult to improve upon in a tangible sense.
The most successful, well-known smoky replacement is Pyrodex, marketed for years as "the smokeless muzzleloading propellant." The Pyrodex patent application was filed on July 25, 1975. Pyrodex, developed by Daniel Pawlak and Michael Levenson, has not been without its problems. Dan Pawlak was killed in January 1977 when his powder plant exploded. The patent application was filed on July 25, 1975. So much for the safety of manufacture; it is a tragedy. Nevertheless, the harder-to-ignite Pyrodex is safer to handle from a consumer perspective. Hard enough to ignite that the "igniter pad" on Pyrodex pellets (made from Pyrodex RS) remains good old blackpowder to this day. Toxicity of Pyrodex persists, though no formal studies have been conducted. Perchlorate poisoning is a well-known issue, as monitored by the EPA.
Though corrosive and toxic, Pyrodex itself has not been easily displaced. The Goex "Clear Shot," held promise, but when this fructose based powder plant caught fire, again someone got killed. That was the commercial end of Clear Shot, and Goex left their distributors hanging out to dry.
Few muzzleloaders today remember "Legend Products Corporation" of Boca Raton, Florida. The patent office reveals that what is known as the Shockey's Gold sticks, or American Pioneer sticks is patented (USPO No. 6,688,232) by Mark Griesbach of Hortonville, WI, and Brett Epstein of Boca Raton, FL. Griesbach and Epstein are the "honchos" behind APP and Shockey's Gold according to their website. Legend Products has vanished from the scene, reinvented as "Clean Shot Technologies" they were sued out of existence for patent infringement by Hodgdon, and now they are back as "American Pioneer."
Clean Shot gained a reputation for extreme moisture attraction, poor and erratic velocities, and resultant poor accuracy. From my own tests, this ignoble tradition continues as American Pioneer and Shockey's Gold. Goex Pinnacle is also manufactured by American Pioneer. The poor granulation and gouged up EZ-Loads that Goex is attempting to market is due to QC and manufacturing over which Goex has no control.
So, despite all the attempts, extremely high quality blackpowder has been hard to replace for those that want smoke, no matter how artificial the product may be. The target matches are hardly reflective of hunting performance; most realize that the best target loads are rarely the fastest thing you can get out of your muzzle. Three pellet loads have won absolutely nothing that I've ever heard of in a paper match.
Nevertheless, matches are not normally won with inconsistent propellants. Right now, all the muzzleloading target shooters I'm familiar with opt for one of three propellants: Swiss Blackpowder, Triple Se7en loose powder, or Black Mag 3. It is not entirely coincidental that these three currently hold the best promise for accurate hunting use as well. All have their pros and cons, easy availability currently being a problem for all but Triple Se7en, but this remains representative of the current smokepole state of the art.
Copyright 2006 by Randy Wakeman. All rights reserved.