I don’t think millitary muskets would be flared at the muzzle because it would possibly negate the use of a socket bayonet. Its possible some Dutch guns were flared, the Dutch tend to pattern their arms for both millitary and civilian use. The 1710 Dutch musket was very similar to the Brown Bess and was in high demand almost through the F&I War, these were still found useful during the AWI, they were often described as ‘old and ugly’ by 1775.Wow! I would have bet all the money in the world (if I had it!) that it's a flared barrel. I could see the .840 though.