Poppin' & Lockin'

From Halopedia, the Halo wiki

Poppin' & Lockin'

Poppin' & Lockin' is an achievement for Halo: Reach multiplayer matchmaking added with the Noble Map Pack. The achievement was unlocked by destroying a vehicle with armor lock. It is represented by the Armor Lock icon over a gold and silver star.[1]

Following the shutdown of Xbox 360 Halo online services on January 13, 2022, this achievement is no longer attainable.[2][3]