how about a really fine single barrel

[King Brown]

In the 60s I made a bet with militia cadets that my mint Brown Bess could provide similar results as their semi-auto FNs on the range (knowing they were green.) Well, turned out not quite but close. The Bess was pooh-poohed by cadets because of stories of poor accuracy of muzzle-loaders. They knew the great battle on the Plains of Abraham in Quebec which won the continent from the Arctic to Gulf of Mexico for the British was fought at close quarters. I doubt the Bess had near the accuracy of American-made long guns. (The 1759 battle was over in 15 minutes; the British held fire and let go at close range in devastating salvos.)