The Marksmen Add-on for Arma 3 has 7 achievements.
Became the Carrier in official End Game multiplayer for the first time.
Completed Showcase Marksmen without injury.
Discovered the secret room in Showcase Firing From Vehicles.
Tried all 7 Marksmen DLC weapons.
Finished any official Marksmen Firing Drill without resting or deploying your weapon (competitive rules).
Completed all official VR Weapon Handling courses.
Finished any official Firing Drill by hitting all targets and spending no more than a single round per target.