In Cleator’s An Essay on Shooting there is a chapter on the range of guns, and he has some things to say I find interesting. Notice the lengths of the barrels under discussion and also their relatively small bore.. This is in England in 1789.
Spence
He explains that the current custom favors the longer barrels, but that he disagrees with the reasons given for the supposed advantage of longer barrels. He then sets out on a long, complicated chapter discussing most of the reasons you’ve ever heard of, involving size of bore, ratio of bore size to barrel length, amount of powder and shot, ratio of powder to shot, granulation of powder and size of shot, how much powder will burn in a given length of barrel, etc., etc. He describes trials made by shooting at quires of paper, counting the total number of hits on the paper, but most especially, counting the number of sheets perforated by each shot.It is not more than fifty years since it was first suggested as a doubt, whether long barrels carried farther than short ones. Formerly every sportsman was provided with pieces of different lengths: the shortest was from 30 to 34 inches in the barrel, and was employed for shooting in cover, where a long piece would be inconvenient; whilst that for open country was from 42 to 45 inches in the barrel.
And the results of the trials and conclusions drawn from them:We have, at different times, compared barrels of all the intermediate lengths between 28 and 40 inches, and of nearly the same caliber, that is to say, from 22 to 26; and these trials were made both by firing the piece from the shoulder, and from a firm block, at an equal distance, and with equal weights of the same powder and the same shot.
From these trials frequently repeated, we found that the shot pierced an equal number of sheets, whether it was fired from a barrel of 28, 30, 32, 34, 36, 38, or 40 inches in length. Nay more, we have compared two barrels of the same caliber, but one of them 33, and the other 66 inches long, by repeatedly firing them in the same manner as the others, at different distances from 45 to 100 paces, and the results have always been the same, i. e. the barrel of 33 inches drove its shot through as many sheets of paper as that of 66 did. The conclusion from all this, is, that the difference of ten inches in the length of the barrel, which seems to be more than is ever insisted upon among sportsmen, produces no sensible difference in the range of the piece; and therefore, that every one may please himself in the length of his barrel, without either detriment or advantage to the range.
Spence