Leaving your handgun in a hot car

[Mark Milton]

Back in the 80s I saw a Raven .25 that partially melted after being left on the dashboard of an old Monte Carlo.

This is not an anecdote.
One of my cop buddies had seen other cheap zinc guns with the same problem.

Some of the RG revolvers would have cracked grips too and I have seen an HR revolver that wouldnt work and I did not know why for years. Later I found out they have a plastic tip on top of the mainspring in that model and I am guessing the plastic tip warped.

It can get up to 198 degrees inside a car on a hot day. In my old neighborhood I can recall seeing heat cause windshields to shatter, which is why I leave my window cracked and my vents open in my vehicle in the summer.
I don't know if thats enough to melt a modern glock or XD, but I have no doubt it will mess with the Zinc junkers still on the market.
You just cant make a good gun out of Zinc. Even smith and wesson tried and failed.

I knew a guy in law enforcement who moved to Florida and he sent me and another buddy pictures of a Glock once with a warped frame supposedly due to being left in a hot car.
I don't know if it was legit or not, but considering the 'soft' nature of the Glock polymer frame (compared to Rugers original polymer guns and the HKs with their fiberglass) it certainly could have been legit.

To be on the safe side I don't carry my Glock around in the summer for that reason though.

I wouldn't worry about an ammo cook off. However, ammo pressures can get high when ammo is stored in a hot place and ammo can lose velocity when stored in cold. We tested that one with a chronograph...

 

[Mello2u]

The issues that come to my mind with leaving a gun in a car are:

1) security of the firearm and
2) degradation of the ammunition.

I would argue that a vehicle is not a desirable place to store a weapon. I am unable to find authoritative information, but I would guess that a significant percentage of firearms are stolen from vehicles. It is simple and quick to smash a window, search a vehicle and steal whatever is available. I think it would be prudent to invest in some device which would slow the thief.

Secondly, I would think that temperatures over 120 degrees Fahrenheit would accelerate the decay of the powder and/or the primer of the ammunition. Instead of a useful life on the order of decades it might be shortened to just a few years. No biggie if you shoot the ammo before it goes bad.