I am a fifty-bore bigot.
The S&W and AE are forty-nine-bores, gentlemen. The chief fifty-bore (bullets sized to .512) is the .500 Linebaugh and its rarer, weirder variant ... the .500 Linebaugh Long. John Taffin treats of them in his engaging book Big Bore Sixguns.
I have a .500L five-holer built on a Bisley frame by master pistolsmith David Clements.. When i had it made, I would trust only three men to build such a gun, which involves machining a cylinder from billet and retiming the gun. These are John Linebaugh "hisse'f", Hamilton Bowen and David Clements. A friend had a .475 built by Linebaugh. Both are sui generis guns, and hoooo doggies touching off a round in either is a sinus-clearing experience.