I met some players last night on 0.50 Stable branch who demonstrated how they are able to dupe items. 1. Punch character in the face to be knocked out, 2. Wait until they regain consciousness, 3. Player is immediately shot in the head (to not damage items) and they then immediately log out, 4. Player collecting the loot waits for all items which are currently floating in the air to drop (5-10 secs) and then items can be accessed, 5. Shot player then logs back in again and still has original gear. Its pretty similar to the old knock out-log off duping technique.

These guys had a backpack completely full of High Cap vests within high cap vests, apparently the key is to put a green inside a black or vice versa or it wont work. Inside the multiple layers of vests were 20 or so ammo tins all full of various ammo, grenades, flashbangs etc. They also said that they had coupled stanag mags with infinate ammo, but cannot confirm.