MK17 damage bug (BUG)

During some test in local play, I found MK17 has some serious bug. We all know that MK17 is the only battle rifle needs 2 shots to kill a guy, but it's not always the case. I found that when you shoot the enemy through arms to the chest, it's always one hit kill, but when you directly hit chest, it needs 2 shots. Pic below.
So the bullet goes through arms to chest lead to one shot kill but a direct hit on the chest will not, hope devs can notice it, thanks
UPDATE: The bullet is also one hit kill when enemy at prone stance. (To the chest)
2_1537071785384_20180916002148_1.jpg 1_1537071785383_20180916002135_1.jpg 0_1537071785383_20180916002052_1.jpg

last edited by ctbear1996

I tested it with both long barrel and normal barrel, results are the same, must be some coding errors.

Interesting. Maybe when it goes through an arm, it (the bullet) considers itself as "in" and no longer applies the armor damage mitigation to the hit when it goes through to the chest.