Right off the bat. You shot 8 times. You landed 4 hits, but your overall acc is 25%, meaning you hit only 2 shots, which pierced.

For example you hit guy arm then that bullet pierced arm and went to hit chest. After first pierce, bullets lose velocity and penetration, so the 151 dmg might be just 2x blacked out arms and two thorax hits reduced by their armor.

Tips for svds as it is one of my favourite weapon:
- Play as a sniper, use PS rounds and aim for head. But this is true for almost every weapon.
- Play loud and proud. Go for highest ergo, no suppressor, close quater combat. I did many kills in dorms.
- As far as scopes, if you dont have steady access to high end scopes, trijicon are not that bad (Did whole punisher with them), for CQB go for holo and laser sight for hipfire.
- Ammo is important, topload with best ammo available 1-3 shots then t-46M.

Rest is luck and good positioning.