Whitworth Correction and the Butterfield Revolver

Ian at Forgotten Weapons posts a correction to his Whitworth video, and explains the difference between Minute of Angle, which is how accuracy is measured today, and Figure of Merit, which is how it was done in the 19th Century. Not only that, the British and the Americans had their own versions that differed considerably.

And, the Butterfield revolver, which though technically very advanced probably did not keep Sam Colt up at night.