The Zombies mode in Call of Duty titles has always been a major way of farming extra XP for your weapons and your account. The absolute mayhem caused by hoards of the undead offers you a chance to get as many kills as you can manage without dying.
Further reading: Call of Duty Black Ops Cold War Might Bring Back BO4 Blackout Map
Black Ops Cold War Zombies has been a major hit among the players as of now. As many of you might be aware, the game is currently offering double player XP as well as double weapon XP. However, Treyarch recently changed that with a new patch update just days after the previous one. But all hope is not lost yet.
YouTuber TheGamingRevolution has a method using which you can farm the maximum XP for your weapon in Black Ops Cold War.
How to farm maximum weapon XP in Call of Duty Black Ops Cold War Zombies
As many of you might be aware, players on PlayStation get an XP boost in the game. So, the first part of this process involves being in a squad with two or more PlayStation players (that is, if you are on any other platform yourself). This will give you an added XP boost for your weapon.
Now, in order to execute this, there has to be a good understanding between the squad mates. What you have to do is ask teammates not to shoot their weapons at all. It is peculiar, but there is no other way around it. However, you can come to the arrangement that when they need to earn the weapon XP, you will do the same for them.
You will have to be a one-man-army, so better prepare for it
Remember that the task of killing the zombies falls entirely upon you, so better be prepared. Now we are at the final stage of the process. Just as you reach the end of the 3rd round, quit the match. This is because as soon you awaken the boss in Round 4, the XP gain rate will drop by a substantial amount. Quitting the match before the 4th round will help you retain the amount of boosted weapon XP you have earned.
If you need to farm more weapon XP, just repeat the process from the first step. Yes, this seems a little tedious, but frankly, the point of the zombie modes is to provide a place for players to let off some steam and to farm XP.
However, note that Treyarch might nerf the weapon XP gain rate for the first three rounds as well some day soon. So it is best you try this out as soon as possible.