"Breech-Loading Gun. Made by John Cookson, and to be sold by him at his House in Boston: a handy Gun of 9 Pound and a half Weight; having a Place convenient to hold 9 Bullets, and Powder for 9 Charges and 9 Primings; the said Gun will fire 9 Times distinctly, as quick, or slow as you please, with one turn the Handle of said Gun, it doth charge the Gun with Powder and Bullet, and doth prime and shut the pan, and cock the Gun. All these Motions ae performed immediately at once, by one turn with the said Handle. Note, there is Nothing put into the Muzzle of the Gun as we charge other Guns." Ad found in Boston Gazette
, April 12, 1756.
Too bad the price isn't listed. This would have been the assault rifle of its day and if Braddock's men were trained to use it (and it could take a bayonet), they might not have been so handily defeated at Battle of the Monogahela.
Recall that this was pre-industrial revolution and that the parts were exactingly fitted by hand. One slip-up and the powder magazine, which was contained in the stock, and you have an Eighteenth Century Ka-Boom!