This is a showdown medal that requires you to get 3 consecutive heavy ammo crates in a single round. However a while ago one of the changes to crucible adjusted how often Heavy ammo spawns, and now its impossible to get the medal/triumph, as heavy ammo will only spawn 2 times a round, and we got every single heavy ammo crate across all 5 rounds (totaling 9 heavy ammo as there was only 1 in the final showdown) Triumph never appeared for either of us. This medal is impossible to achieve and no ones noticed because of how infrequent Showdown appears.