Gough Thomas reports on a "blind" test conducted in England, in which shooters were asked to fire two different loads that were identical in terms of shot charge and velocity, the only difference being the powder. They were unanimous in selecting the load with the faster burning powder as producing less recoil. Going strictly by measurable recoil, that seems logical because although the shot charge and velocity of both loads was the same, you use less fast burning powder than you do slow burning powder. Thus, the total ejecta weight is reduced in the load with faster-burning powder. Not much difference in terms of weight, but perhaps enough for the shooters in question to notice a difference.
