i had some of Thomas' books and got rid of them because there was nothing in them i needed long term but my recollection parallels millers in that thomas didn't test anything, he reported something done by someone else.

as to the weight of the powder in the ejecta, in shotgun shells smokeless powder is of utterly no consequence. 30 grains of powder versus 437.5 grains of shot at least, that's not even 1%. you can calculate the effect but it would take something more precise than a human shoulder to ever detect so the difference in weights between fast and slow powders isn't even worth bringing up.

and finally, people need to learn the difference between energy and force. everything mentioned so far relates to kinetic energy which is a function of mass and velocity. unfortunately your shoulder doesn't feel energy; it feels force. force is a function of mass x acceleration. the faster you accelerate a shot charge down the bore the more force is generated.

you can shove 1oz of shot out a muzzle at 1100fps that was accelerated slowly up the bore and another oz at same velocity that was accelerated rapidly and you'll get the same kinetic energy of recoil but the FORCE of the latter will be greater. that's an immutable law of physics in the universe we live in and any test that shows results contrary are skewed, biased, jsut flat done wrong or misrepresented to prove a point.

annecdotally, i had a flat each of B&P anagrina's and high pheasants. same pressure, IIRC same velocity, and the high pheasants were a heavier payload. the anagrinas are loaded with lighter charge of faster burning powder and were vicious by comparison, so much so i quit shooting them in my A&N SLE because of concerns over what the recoil was doing to the skinny wrist on the gun. by all rights of gough thomas and the kinetic energy math, the field loads should have kicked harder. they didn't.

as an aside, anybody know where i can find reloading data on B&P 2.5" shells? i've got 500 of them i can't do anything with.

roger