The "road agent's spin" is the famous move Clint does with his pistols at 4:00 minutes into this clip. My dad taught me how to do this move on an old black-powder revolver. Clint is much smoother than I ever got.

It's often mislabeled the "border shift" which is a different maneuver involving tossing your empty gun from your firing hand to your off hand, while simultaneously tossing a loaded gun from your off hand to your shooting hand.

"Road agent" is the American western term for what the English would call a "Highwayman", i.e. a horse-mounted bandit.

Interesting fact: In Britain, a Highwayman was considered a higher class of criminal than a mere "footpad", because at least the highwayman could afford to keep a horse.

Better to be robbed by the poor and aristocratic, rather than the merely poor.