so anyways I was having a fun knife war and a guy was using his gravity gun so I knife him and hit his head when I notice he is using a knife at the time I killed him...
So anyways I was walking over his dead body and it kept telling me to press f for gravity gun http://prnt.sc/e2xxvt so I did and tons of gravity guns spawned out of that spot and I had infinite grav ammo..
I don't know why this occured.