For some reason I've always felt like racking the slide on a pump gun of any sort was the most reflexive way to cock/recock any firarm. No evidence, just my opinion about what came naturally to me. Little or no practice? ,pumps get my vote for being simple,reliable, instinctive. In a shotgun it is so much more effective of a round that it just seems to make the most sense no matter how I look at it.
Gaily bedight, A gallant knight In sunshine and in shadow, Had journeyed long, Singing a song, In search of El Dorado