It is also worth noting I think that the early smokeless powders were not really progressive burning. When these powders were loaded to give ballistics similar to the familiar BP loads they produced higher peak chamber pressures than did black. When loaded to similar pressures to Black these "Fast" smokeless powders will give
lesser ballistics than black. When the slower more progressive powders are loaded down to BP pressures many of them will prove unreliable, particularly as the temps fall as in many hunting situations. For the most part they were not truly designed to produce low pressure, but to allow heavier payloads, higher velocities or Both. Except for the mess BP is near about a perfect shotgun propellant.
