6-7K Hits SHOULD only occur in the red zone. As has been stated by Dev's (and this SACKS) it is the Red Zone on the server, not the client. They don't always match, and that is LAG [AGGGGGGG ... toss the device and scream].
But players who get One Hit are not ALWAYS getting 6-7K damage, some times it is much lower, but consider if a boss hits for a nice low 2K (after armor) and you have 3K health. Boss can EASILY hit you twice in a mini-lag-spike ... once again causing you to toss the device and scream.
Hmm, wonder if it is no longer Lag, and more that my poor device has been tossed so many times

Bookmarks