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This script will help you to use weapons like : G3, M14, M21, Barrett, Dragunov, and the pistols, this also works for the modern paintball mod. If you use this script with normal weapons such as ak47, ak74, m4 carbine etc. It will affect their speed too (not recommended).
Autohotkey:
How to use:
1. Install Autohotkey
2. Extract the script to your desktop
3. Double click the script
4. Go ingame, toggle on/off with F6
5. Enjoy