From the Cabela's website
Pyrodex® RS can be used in all calibers of percussion muzzleloading rifles and shotguns. It has a wide application of uses and is the most versatile powder in the Pyrodex® line. Like all grades of Pyrodex®, it burns cleaner and produces less fouling than black powder. RS compares to 2F black powder on a particle size basis.
Select is considered by many the most accurate powder available. Select is an enhancement of our RS grade of Pyrodex®. Using RS or 2F data in a volumetric measure, Select can significantly reduce group size. Wonderful news to the deer hunter is that Select performs well with sabots and conical bullets. Select has also become a favorite among many black powder cartridge shooters because of its exceptional consistency. For target use it is the "best of the best".
