So on ps4 I joined a random game and shortly after another player joined but straight away I noticed something worrying.
So we were just running around taking out whatever tanks and harvesters we came across but this new player was running around with the exp pistol except the pistol was firing rpgs like a machine gun.
I personally witnessed him on more than three occasions taking out fnix tanks in less than 5 seconds and to confirm something was iffy when in a house he was firing his gun at us and the whole house was shaking like when rpgs hit and the furniture was moving.
If these mods or whatever are out there its only a matter of time before there everywhere and really spoils the game this behaviour.