I found it hard to find a list myself on which weapons are needed for the achievement so i logged every weapon i did put a suppressor on. As of 20 November 2024 when i last checked it and heard this list works.

Not every weapon can be suppressed. For the ones you can you will need a "Baffle Kit". I got them from the mega zombies, air drops or in high loot zones. Some Deadzones zombies drop a Baffle Kit faster i noticed. Keep in mind you will need a Gas Mask to survive in there. They run out so if you are slower in killing zombies you might want to make multiple.

When you have a Baffle Kit you want to open the Crafting Menu and go to the Bullet Tab. There you will see a option to suppress the gun. You can also do it in the inventory (not in hand slots) by right clicking and pressing suppress. Sometimes the list is long and you will have to scroll down to see the option.
Note: Some of my friends did not get the achievement by doing it in the inventory, so maybe to be safe do it it the Crafting Menu.

Most Weapons need 1 Baffle Kit but some there are some that need multiple. I think it goes up to 3. Besides that to suppress dual guns you will need to put a silencer on each of them and then combine the guns to make them dual.

A tip is to remove the suppressor from the weapon to get your Baffle Kit back. You do this the same way as putting it on.

• Assets
  
• Bisey
  
• Blunterforce-12
  
• Centare
  
• Cryogen
  
• CSO-85
  
• CSO-85-BLK
  
• DUAL Intragat
  
• DUAL Iridium Tanto
  
• DUAL M1911
  
• DUAL TANTO
  
• ECS-25
  
• Empey
  
• Falcon .50
  
• Frostbite
  
• Goverment "Vaquero"
  
• Government
  
• Intragat
  
• Iridium Tanto
  
• Kompact
  
• M1911
  
• Nacht
  
• Private
  
• RSS-03
  
• Sundoor
  
• Tanto
  
• Tempest
  
• Tonijn
  
• Tukavtomat
  
• Ulfberht
  
• Uzey
  
• Valhalla SGNL-512

This is all the weapons i did until i got the achievement. Same for my friends.

Good Luck with the achievement!

I cant keep this update to date but i will try to do my best. Check comments because sometimes they mention if a weapons is added to the list.

Below i will try highlight comments that give additional information about the list!