Miller, I believe I sent you--or someone else on this BB who requested it--a copy of the chapter from Thomas' book in which he addresses the above subject. To summarize, the experiment in question--by IMI--involved "nine experienced shots of various build, shooting under a wide variety of conditions with guns of different types, weight and boring. The cartridges were all loaded to give the same velocity to the same shot charge, though by means of powders of various rates of burning. The shooters did not know what they were firing, but were merely required to give marks for recoil. They were unanimous in assigning the lowest recoil to the cartridges loaded with the fastest-burning powder, the dynamical effect of which was checked throughout by electric accelerometers built into the stocks of the guns, and their conclusions have since been widely confirmed."

Since no particular brand of cartridge (nor powder) is mentioned in the text, that would seem to remove any potential "bias" from the experiment. That is, the company trying to prove that THEIR shell (or powder) recoils less than the competition. Besides which, if the company in question makes various types of shells and powders, what advantage is there in promoting one of their own shells (or powders) over another of their own shells or powders?