Trigger
The mechanism the shooter operates to release the sear and fire the rifle. Light, crisp, and predictable beats every other characteristic.
A precision trigger has three jobs: predictable break weight, minimal creep (movement before the break), and minimal overtravel (movement after the break). Two-stage triggers (a light take-up followed by a clean break) are the standard in long-range competition.
Replacing a factory trigger with a quality aftermarket unit (Bix’n Andy, Trigger Tech, Jewell, Timney) is one of the highest-payoff accuracy upgrades you can buy. Often more impactful per dollar than upgrading the optic.