Ok so I have created the ultimate debug build and it's going to be annoying as heck - but if you could record this when firing your gun, when using a melee weapon, and then when the enemies are attacking I can use/pause footage to see the message. https://www.dropbox.com/s/ell7e3yx263p6h9/Super debug duster build.zip?dl=...
Revolver test : https://www.youtube.com/watch?v=Y0GUcchXjSo&feature=youtu.be
Melee and enemy test: https://www.youtube.com/watch?v=pew-u2MRGpU&feature=youtu.be
There seems to something going on with timers taking much longer than they should... You'd probably recognize the issue right away haha. I really hope this helps!
So this seems to be a bug in international settings from what I can tell - for example the cooldown of the revolver is 0.53f, but your computer is making it 53.0! At least now I know what the bug is, and it is fixable. On the off hand that its an easy fix, would you mind trying this build and seeing if it works for you? No need for recording. https://www.dropbox.com/s/gya2v2ypd1f3a39/Duster INTtest.zip?dl=0