Just don't leave one lying on the dash of your car in Phoenix in late July.
6/6 Nylon is only rated to 180f. Glock and others are made from 6/6 nylon with a mineral or glass fill. Not many plastics are rated above that unless they are PTFE or Vespel based polymers. What I am getting at is the gun may not melt but certainly loses strength well before 400f. A bigger issue may be below 30f.We've been over this many times of this forum. You need temperatures around 400 degrees Fahrenheit for Glocks to melt. Unless that car spontaneously combusted I have my doubts on the validity of that picture.
6/6 Nylon is only rated to 180f. Glock and others are made from 6/6 nylon with a mineral or glass fill. Not many plastics are rated above that unless they are PTFE or Vespel based polymers. What I am getting at is the gun may not melt but certainly loses strength well before 400f. A bigger issue may be below 30f.