Gough Thomas reported a "blind" test in which shooters fired ammunition in which the major factors impacting recoil-- shot charge weight and velocity--were the same. Only the type of powder (and the weight of the powder charge) was different. The shooters unanimously selected the shells with the faster burning powder as having less recoil. Maybe explained because the weight of the faster powder was lower than that of the slower powder, and the recoil formula includes ALL of the ejecta (wad and powder, as well as shot)?
