Will modern ammunition "cook off"?

[allingeneral]

I've been carrying a box of 50 .38 specials in my truck for the past couple of months hoping that I might get a chance to use them at some time or another. The weather's getting hotter and the thought came to mind - will the heat inside a vehicle ever cause a round to "cook off"?

[Moccasin]

I don't think the temperatures inside a vehicle would get high enough to cook off ammo, unless said vehicle is on fire. I would think that you could check the manufacturers website and get information about safe storage temperatures. The elevated temperature might cause a chemical change in the ammo, seems that happened to powder used on a battleship years ago.

[Bob]

I'm sure Moccasin is right it isn't hot enough, but I have been told that extreme temperature exposure both hot and cold could effect accuracy. I don't know how true that is, with 38's I don't think you have a problem. I sometimes leave shotgun ammo in my truck for a long time and I never saw any difference in performance.

[fiasconva]

There is no way it could get hot enough in your vehicle to set off that ammo. I have never read or heard of that happening. That ammo that went off in the battleship was WWII vintage and had become very unstable after all those years.

[SnakeEater]

I have asked this question before when I lived in AZ, since I could not take my gun in the work area but could leave it locked in my truck. AZ 120degree days make for one hot truck. I was told it would be fine. It would take a very hot fire and an act of Congress to get them to pop. I was more worried about my polymer pistol melting cuz I could not hold it to put it in my holster. Ouch. A firefighter bud told me that he is not too worried about ammo in a house fire unless there is natural gas in the house else the fire won't get hot enough to pop them. They did this on Myth Busters as well and I think it took a very hot fire to ccok off the rounds.

Short answer is yes but it takes alot of heat.

Will