1-Go to Virtual Arsenal.
2-Equip your character with the GA Carrier Rig (I choose DIGI camo and the AAF version).
3-Equip Katiba 6.5mm weapon.
4-Click preview and go to any group of standing AI.
5-Go to the back of any of them, and select single fire mode.
6-Shoot one shot by one shot (to ensure how many bullets needed to kill him).
7-Go back to virtual arsenal and change the weapon to any of these: Carbine Katiba 6.5mm, Katiba GL 6.5mm, MX 6.5mm, MXC 6.5mm and MX 3GL 6.5mm
8-Repeat the test from the step 4 with all of these weapons