This guide will show you how to get the M4 in the 4.0 update.
Description
This is a guide that will show you one of the easiest ways to get the M4 in the 4.0 update.
Finding the code.
First, you will have to find the code. The code will likely be on a piece of paper. The location of the code and the code is randomized every time. The code is needed to open the gun safe that you will find later.
Finding the firewatch tower.
Now to unlocking the gun safe. You will need to go to the firewatch tower. The firewatch tower is on the hill to the east of the RV.
Unlocking the gun safe.
Once at the gun safe, you must insert the four digit code that you found earlier. if you hear a buzz and not a beep, then you input the code wrong. If you hear a beep, then that means that the gun safe is unlocked and you may now have your shiny new M4CL!
TL:DR
Find the code for the gun safe somewhere around the map, go to the left of the RV until you find the firewatch tower, insert the code and get the M4.
Conclusion
Thank you for reading my guide and have fun with your new, fully automatic M4!
Thanks to underrated for his great guide, all credit to his effort. you can also read the original guide from Steam Community. enjoy the game.