McCree has one of the biggest burst combo in the game if you're target is at close range. As illustrated below, you wanna throw your flashbang (E) to stun the target, then, while fully loaded, you want to use Rapid fire (Right mouse click), followed by a roll (Left Shift) which will auto reload your Peacekeeper. Finally, use that Rapid fire once again which is fully loaded to finish off your target (If it's still alive).
