After killing someone a friend and I looted his body and when one of us dragged his gun to our inv it stayed behind on the looted body, and if one of us walked away and pulled the gun out into our hands and the other looted the gun from the body it would cause the gun in the other persons hands to be put away and then it would go missing from the first persons inv. The only thing I could determine was that we both dragged the gun over to our inv at the very same time which caused 1 or our own 2 guns to completely vanish from the game as we both had m4s and the dead person had one as well, so after it was all said and done there were still only 2 guns