Obtaining all weapons in Atomic Heart lets you experiment and try all of them to find out which one is best for your style.

It is also vital that you upgrade them using the attachments and items that you can find in different places.

That said, you can find both weapons and upgrade materials inside chests. One of them is a secret chest that specifically contains weapon blueprints.

Here’s where you can find it.

Where to Find the Secret Weapon Blueprint Chest

Source: DPJ

In one of your early quests in the game, you will be tasked to cross the Seed Bank. This is part of the In Hot Pursuit quest.

However, most players don’t know that around this area, there’s actually a hidden chest located somewhere.

Source: DPJ

To get there, let this safe room serve as the starting position. As you leave the room, you will find a pile of containers that you can use to climb your way up.

Walk straight from there and turn left twice. It will then welcome you with large metal shelves. Walk past the shelves by traversing the narrow path that you will see on the right side.

From there, jump over the first platform that you can reach. Once you are above it, this is where you have to test your parkour skills.

Source: DPJ

In your current position, jump and hang on to these two metals sticking out of the next platform. Use both of them to boost yourself up.

Source: DPJ

As you climb up, look up and you will see a yellow chest. Find your way up there and get the hidden reward. The items inside will vary depending on what weapon you currently have.