WW Greener's "recoil machine" registered up to 200 pounds recoil. It is pictured in his 9th Edition of "The Gun and it's Development".

The 4 bore, with a 12 dram (328gr.) load was enough over 200pounds that it broke the machine. He did not get to test the full 16 dram load of 437gr. This,I believe was with the 1/4 pound round ball of 1,750gr. - but might have been the slightly heavier conical.

Some of the extra recoil of a black powder load, is due to the fact that 56% to 57% of the charge weight, remains as solid waste and is ejected out the muzzle with with "ball". Some small amount stays inside, making a thin layer inside the bore, being then known as fouling. The ejected waste adds to the projectile weight - ie: 'ejecta' as far as recoil is concerned, just as wads also add to the projectile's weight.