3 more things: I was able to make the fire pistol have infinite ammo somehow, the LMG will continue to have piercing all the way through a reload if you keep the button pressed down, and I also managed to gib myself on a lift lol. That last one may be intentional now that I mention it.
Edit: just noticed that filling grenades from the cache in the exterior of the robot factory (in pic) changed my grenade type from rotvine to frag.