In the first video the initial shots hit the arm, and once bullets land in the torso the AI dies rapidly. The second video has shots aimed for the legs and not the torso which results in the AI taking many rounds to die.
The third video does not appear to be on a UO sever, so no comment.
The fourth video shows several AI dying from a single aimed burst from an LMG. The AI that did not die was fired upon at a rapid rate from an LMG. The first bursts missed be a wide margin, and once the fire is put on target the rapid rate of fire combined with an LMG spread makes the fire have a large spread.
A short overview of the ACE medical code shows that it treats both players and AI the same, unless ACE Medical is configured to. From the UO wiki ACE Medical is configured to tread AI and players the same. These values appear to be set by a serverside addon, so to test ACE Medical damage they must be set manually.
Basic testing has unarmoured AI being critically injured from one to three shots to the torso and one or two shots to the head. The times it took two shots to the head the first bullet appeared to have grazed rather than hit dead on.
Against RHS Russians with 6B23 vest it took one to five shots to the torso to critically injure them.
The testing was done using CBA bullet tracking, getAllHitPointsDamage, and ACE Medical values set according to the ACE Server Config. Shots were fired from approximately 300 meters with an M16.
The bullet tracing and getAllHitPointsDamage showed many shots which appeared to hit the head or torso either missed by a narrow margin or impacted another body part. It also showed an increase in hits to the extremities when firing at a rapid rate, rather than aimed shots taken at a standard rate.
This is all consistent with the videos shown. AI are killed from shots to the head and torso, but do not die from shots to the extremities. When firing at a rapid rate more shots hit the extremities which means more rounds are required to kill.
Can anyone reproduce damage issues in a controlled environment?