i've been puzzled for a long time about references in the 18th-century literature to shooting at what seem unrealistic distances, forty yards, fifty or even longer. That makes me suspicious we have yet to figure out how the old boys loaded their smoothbores. Here's a good example, testing a cylinder bore gun in a way I would never think reasonable.
Spence
A Treatise on English Shooting; with Necessary Observations for the young Sportsman when out and returning home, by George Edie, Gent., London, 1773
The internal goodness of a Piece can only be known by trial, without which no new one should be purchased. For the purpose of trying a gun, the following hints may suffice; tack up a large sheet of brown paper, with a card in the middle, on a clear barn-door or some such place, that the degree of scattering may be the better observed; stand at about the distance of seventy yards, and try at first the common charge of a pipe of powder, and a pipe and half of shot ; and to do the gun justice, be as steady as possible in your aim: if you find you have thrown any at this distance into the card, you may safely conclude the Piece is a good one; or if you have missed the card, perhaps through unsteadiness, and thrown a tolerable sprinkling into the sheet, you may have the same good opinion of the gun ; but if you find none in the sheet, and are sensible of having shot steady, try then an equal quantity of powder and shot (which some barrels are found to carry best) at the fame distance; and if you then miss giving the sheet a tolerable sprinkling, refuse the Piece, as being but an indifferent one, if you are determined to have one of the best sort, which certainly is most advisable : and this trial may be reckoned altogether sufficient for a gun that is recommended by any gunsmith as a first-rate one. But for the second, or more indifferent sort, let fifty-five or sixty yards be the distance of trial, and a judgment formed according to the above rule: but it must be observed, that as some Pieces carry a larger quantity of powder and shot than others, so it will be advisable to try three or four different quantities; but never to exceed a pipe and a half of powder and the proportionable quantity of shot as abovementioned.
Spence