I got  it one prestige and its the only time i've gotten near it too

Joined a game of dropzone to level up blast shield,the other team had a group of quickscopers with tac inserts (surprisingly common in dropzone) and just kept dropping them everywhere around the zone,didnt even have sitrep on

Ive noticed it happening in dz since too it seems all qsers have moved to dropzone but havent really gone for the challenge since

good luck dude

(also not sure if the challenges count until the tac insert is unlocked so may be worth looking into)

play hc dom or kc, tac city.

i have it its easy to get just play infected or drop zone people use them respawn tacs in those game modes duh! ahaha just saying its easy