User blog comment:ILoveBattles/ILoveBattles (Collab with WanderingSkull) - Season 1 - Episode 4 - James Gang vs Dutch's Gang/@comment-4661256-20160224030813/@comment-4661256-20160224035828

Jesse James was a bushwhacker. Bushwhackers were ambushers, raiders, and fast-movers where a skill like quick-drawing would be very necessary in striking first, striking quickly, and getting away. While you may be accurate in your claim it's not outside the realm of plausibility that he was quite skilled as a gunslinger.