here i show you how to get the Vector .45 into Far Cry 5:
How to Revert Far Cry 5 game to 1.0 and enable the vector when you return to current version. All you need to do is move around and rename files in the game folder.
Guide:
Go to your Far Cry 5 installation folder and move patch.dat and patch.fat somewhere else safe (you'll need to restore these later). These are the 1.2.5 files - we dont want these right now as they disabled the vector on 1.2.5 save files. This is why we need a save file SAVED on 1.0 version.
Make a copy of common.dat and common.fat in a seperate folder. Leave the original files intact in the game folder. The game needs these to launch properly.
Now rename those "common" copied files to patch.dat and patch.fat respectively. This is how we revert the game to patch 1.0.
Copy them both back into the game folder.
Now you're ready to Launch Far Cry 5 in 1.0 patch state. Now load your save game and do anything to save the game (use the save game option if you like). Make sure the game does the three dots animation that it's saved. Now you have a 1.0 save file.
Quit Far Cry 5.
Now simply copy the backups of the original patch.dat and patch.fat back into the folder overriding the "fakes/overrides" (1.0 files) we made earlier. This will restore the game to current version (1.2.5 or w/e).
Now launch Far Cry 5 again and go to the Shop. You will now find the Vector ACP .45 Classic available for sale immediately - I unlocked it immediately after leaving dutch's island to test this fix. So it should work no matter where you are.
Now enjoy your new Vector!
Thanks to Reddit
Greets goldendrake