The game uses built-in mouse acceleration for things like making it harder to aim up and down when holding a hostage in your left hand. However, this also interferes with regular aiming and can make you feel really skill-issued when none of your muscle memory is working.

Go to C:\Users\(Your PC Username)\AppData\Local\PAYDAY3\Saved\Config\WindowsClient.

*Enable hidden folders if you don't see some of the folders. To do this in Windows 11, you can click View in File Explorer and under Show, tick Hidden items.

Open the Input.ini file.

If you disabled Mouse Smoothing in the game settings, it should look like:

[/script/engine.inputsettings]
bEnableMouseSmoothing=False

Literally all you need to do is, below this add bDisableMouseAcceleration=True. It should look like this:

[/script/engine.inputsettings]
bEnableMouseSmoothing=False
bDisableMouseAcceleration=True


Save the file and close it out. This Unreal Engine 4 setting disables all of the mouse acceleration in the game and you will immediately notice the difference. (At least, I did.)

You'll be able to look up and down with a hostage with no slowdown either. Hopefully needing this tweak gets fixed in a patch. You thought you were popping helmets before, but now you'll be sending them flying.

Note: you should also do this to the WindowsNoEditor folder as well, just in case. They might be different folders for the open beta and the full release builds.