The M13B Assault Rifle is one of three new weapons added with Modern Warfare's Season 1 update. However, while the other two are unlocked through the navigation of the Battle Pass, this one will require you to venture into the new DMZ mode released alongside Warzone 2.0. You'll need to complete a specific mission to get your hands on it. Here's how to unlock the M13B for all game modes in Modern Warfare 2.
Unlocking the M13B in Modern Warfare 2
To unlock the M13B for usage, you'll need to enter the DMZ and kill a boss named The Chemist. This is because he is holding the M13B hostage, and you need to steal it from him to use it yourself. However, this is easier said than done.
To begin, enter the DMZ and open your tactical map to get a lay of the new land before you. On the map, you should see a purple radiation symbol that represents the relative location of the Chemist. By any means necessary, you'll need to reach this location to kill the Chemist, but make sure to gear up by looting buildings on the way. The Chemist is surrounded by his own heavily armored army, and his general location is obscured in toxic fumes, so you'll need to make sure to at least have a gas mask on you before you enter. We highly recommend having a maxed-out vest, stims, and a syringe gun for self-revival before approaching his domain.
Once you've reached his location, carefully scan the area for a soldier wearing a yellow hazmat suit, holding a yellow gun in his hands. This is the Chemist, and the gun mentioned is the M13B prize you're searching for. Like his PMC, he is heavily armored and will require some firepower to bring down. Prioritize headshots and take your time lowering his health. Occasionally, he will throw out a cluster of smoke grenades to hide his location and retreat. Follow the trail to keep up with his pace. With enough damage, the Chemist will fall and drop his kitted-out M13B. Pick it up and head to extraction ASAP. Even with the gun in hand, you can still fail to unlock the M13B if you die before successfully extracting it. Should you succeed in extracting, you'll receive a notice that you've unlocked the weapon during the mission debrief.
Additional tips for dealing with The Chemist
The Chemist can be a difficult encounter for those unprepared. Here are a few tips for dealing with him:
- Run Him Over - The Chemist is still just a man, and just like any man, he can become roadkill with a big enough vehicle.
- Snipe Him - The Chemist's domain is often surrounded by tall buildings perfect for hunkering down with a sniper rifle. Plink him down from a safe distance.
- Squad Up - Even though this fight is soloable, we recommend taking a squad with you to mitigate your error margin. By yourself, you'll need to be ultra careful, as you can be put down in just a few shots, even with armor. Only the player holding the M13B will unlock it upon extraction. However, the requirement to unlock the M13B is only to extract with it equipped. Your squad can share the gun and extract using only one M13B drop. It doesn't even have to be the Chemist's specific variant, either.
- Gas Masks are Limited - While you're in the Chemist's domain, your Gas Mask will slowly begin to deplete itself. Once it's depleted, it will break, and you'll be vulnerable to toxic gas. Fortunately, his armored entourage are all rocking additional Gas Masks for you to plunder, should the need arise.
For more guides, news, and info on Modern Warfare 2, check out our guide on How to unlock all Operator skins from Battle Pass in Warzone 2 right here on Pro Game Guides.