It takes way too much shots to put down an enemy with rifles of 7.62 caliber (marksman rifles). Shooting at center mass is just annoying since it takes 3-4 shots at least to have an effect. Targets that have been hit in the body center (visible "blood mist" upon the hit) are still able to fight back normally. Headshots are not lethal from time to time, even after the direct hit in the face. Overprotecting body armor or underpowered ammo may be an issue.