RDR2: Speed Shooting with the Springfield Rifle

It is my opinion that the Rolling Block rifle is the best long-range weapon in Red Dead Redemption 2, and I know some folks disagree with me on that, but it does not become available until much later in the story - the mission, ''The Sheep and the Goats''. But thankfully a similar weapon is available early on, the Springfield Rifle.
Fully kitted out and with a medium-scope on it, its the poor cousin of the Rolling Block, and it is for this reason that I privately refer to it as the ''poor man's rolling block''. It is an excellent and formidable weapon, especially when hunting or for eliminating scum like the O'Driscoll's as demonstrated in this presentation.
Arthur Morgan demonstrates SPEED SHOOTING with this weapon, racking up five kills in EIGHTEEN SECONDS. It could have been quicker even than this, were it not for my needing to confirm that a running horse wasn't an enemy, and an enemy that was running and passing behind the bridge was in fact a threat, but the real slowdown issue was an enemy who I grazed and had to kill last. Nevertheless, eighteen seconds isn't bad given the odds.