How to unlock the CARV.2 in Warzone
Debuting during the first half of Season 3, the CARV.2 can be acquired through the use of a shop Blueprint or in-game challenge.
To unlock the CARV.2 in Warzone and Black Ops: Cold War, you must rapidly kill two or more players in 10 different complete matches using Tactical Rifles.
There are a few exceptions with this. If you happen to hurt an enemy before you die and one of your teammates gets the kill, giving you the partial kill, it won't count. The same applies if, for example, you get a kill and then get a second one with a proximity mine or any other explosives.