Not sure if this'll work for you, but I just replied to another thread here on the same matter. A quick copy & paste:
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1.
Getting your video.scr configuration file to work. In my case, the video.scr file worked immediately, with no additional tweaking required. On Windows 10, for me, this file was located in
C:\Users\USERNAME\AppData\Local\Techland\COJGunslinger\out\Settings (the AppData folder may be invisible for you, but can be navigated to by either typing in the path in the address bar or by displaying hidden folders in the settings). If you're able to modify settings in this file and see those changes reflected when you start the game, you can skip to point #2 (if that's applicable).
One reason that the file may NOT be working for you is if you are missing a registry entry - or the registry entry differs - specifying where this file (or rather, collection of files and directories) should exist. If you're comfortable using RegEdit, navigate to the folder
HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Techland\cojgunslinger - and if the registry folder does not exist, create it. If it's not already there, within the
cojgunslinger folder you will need to add a new String, and rename it to 'writedir' (without the apostrophes). Then, edit that string to contain the Value Data '
Techland\CoJGunslinger' (again, without the apostrophes). This is the subdirectory path under
C:\Users\USERNAME\AppData\Local, from which the application will look for the various configuration files (so, the complete path eventually being '
C:\Users\USERNAME\AppData\Local\Techland\COJGunslinger' - with further files and subfolders generated within that).
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There are a few other bits in the other thread that may or may not be of interest to you, regarding anti-aliasing and stuttering which you can read over
here.
Hope that's of some use - let us know if tweaking the registry worked as this isn't something I could verify from my side as I didn't have the problem.