Three brand new weapons were added to Modern Warfare 3 and Warzone with the Season 1 update which brings the XRK Stalker into the roster. But you need to unlock the sniper first and I can help you earn it in this guide.
How to Get the XRK Stalker in Warzone and MW3
To unlock the XRK Stalker, you need to earn at least 15 Battle Pass Tokens to complete sector A4 of the full map. Every new weapon that is added at the start of a COD season will be tied to the Battle Pass as free content, so that includes the RAM-7 and the Stormender as well. Luckily, you can choose which ones you earn first.
If you spend your Battle Pass Tokens wisely, you can head north on the sector list starting at A1 and ending at A4. Each sector requires five tokens to complete and provide access to the next section of the map. Token 15 on this path will complete A4 and provide you with the XRK Stalker for use in loadouts across all game modes.
Earning Battle Pass Tokens is another story. These work the same way as standard XP, so all you need to do is grind out matches and passively make your way to more tokens. If you have double Battle Pass XP or the Black Cell pass, then you can get to the other sectors much faster. Before you know it, all the new guns are yours to use.
Your last method to earn the XRK Stalker is to extract the weapon from MW3 Zombies. You can either find the weapon out in the open world of Urzikstan or you can have a friend drop the weapon from their own inventory. Extracting ensures the new sniper rifle is yours in Warzone and MW3.
For those of you who take the new weapon into Warzone, make sure you have the best Perk Package possible.