Shoot and Scoot Achievement in Halo: The Master Chief Collection

This achievement is best done in a Co-Op playthrough where you’re teammate utilizes their Sniper Rifle to take out the enemy opposition through the mission. It’s a generally short mission, so it won’t take this one player too long to kill the Covenant forces on route to the objective. If you’re itching to help your teammate out, simply swap your Sniper Rifle out with a different weapon and you won’t need to worry about accidentally firing the rifle and voiding the achievement. 

All in all, once you’ve reached the final platform, both players will most likely be swapping their Sniper Rifles out for Plasma Pistols, Rocket Launchers, and detached/mounted Missile Pod Launchers. However you decide to approach this mission, once you trigger the mission’s final cut scene, this achievement will unlock provided you didn’t fire a single shot from the Sniper Rifle.