This mod adds the hitmarker sound and a kill sound (UAV) from COD MW2.
Requires Advanced Crosshairs, Hitmarkers and Hitsounds: https://modworkshop.net/mod/29585

Installation Instructions:

• Ensure that Advanced Crosshairs, Hitmarkers and Hitsounds is installed and working correctly.
• Download the .zip folder from the link above.
• Extract the entire 'COD MW2' folder from the .zip into your 'mods\saves\ACH Addons\Hitsounds' Folder.
• You can now modify your sounds from the 'Mod Options' -> 'Advanced Crosshairs, Hitmarkers and Hitsounds' -> 'Hitsounds' menu.

I do not take any credit for the sound files used. I just made them into a mod.