by Timothy P. Banse
It's as simple as dirt. Pyrodex weighs less than blackpowder (roughly about 70% as much as blackpowder). However, since Pyrodex yields more energy per pound than blackpowder, the exact same volume of Pyrodex lends performance similar to blackpowder.
Suffice it to say Pyrodex loads are measured by volume, not weight. All grades of Pyrodex burn cleaner and produces less fouling than mere blackpowder. Due to Pyrodex being 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.
Granular Pyrodex is available in three varieties: RS, P and Select. Use Pyrodex P as a direct replacement for FFFg Black powder (when measured volumetrically using a black powder measure) in muzzleloading pistols, cap and ball revolvers, and in small bore, muzzleloading rifles. Pyrodex may be used with standard cap, musket caps or 209 primer ignition systems.
Slower burning RS compares to FFG blackpowder on a particle size basis. Use Pyrodex RS in all calibers of percussion muzzleloading rifles and shotguns (Note: we didn't say anything about pistols.) Pyrodex RS boasts a wide application of uses and is the most versatile powder in the Pyrodex line.
Pyrodex Select is an enhanced formulation RS grade of Pyrodex. Using either RS or FFG data in a volumetric measure, Pyrodex Select can significantly reduce group size. It performs particularly well with sabots and conical bullets. Pyrodex Select is also a favorite among blackpowder cartridge shooters due to its exceptional consistency. For target use it is said to be the "best of the best."
Finally, be advised that burning Pyrodex leaves behind corrosive residue, albeit, the fouling is softer than the crud produced by blackpowder. Just like with conventional black powder, firearms burning Pyrodex should be cleaned with natural cleaning solvents.