How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask ProShooter Your Own Question
ProShooter, Firearms Instructor
Category: Firearms
Satisfied Customers: 4126
Experience:  Certified Firearms Instructor and Glock Certified Armorer.
Type Your Firearms Question Here...
ProShooter is online now
A new question is answered every 9 seconds

I have a S&W 9mm Sigma handgun. I am wondering what are

Customer Question

I have a S&W 9mm Sigma handgun. I am wondering what are the chances to go off by itself if is chambered and kept inside a car where temperatures can reach.... 130-140F... I guess?
Submitted: 1 year ago.
Category: Firearms
Expert:  ProShooter replied 1 year ago.

Good afternoon,

My name is ***** ***** I am happy to help. As a firearms instructor, I receive this question a lot. While not impossible, it is very unlikely that the round will "go off". Ammo should, in theory be kept at normal room temperature, but there are studies that have been done where ammo can be raised well above room temps and won't go off. There is another issue though of the heat warping the shell casing and causing an issue with those cartridges when you do plan to fire them. Think about a glass jar with a metal lid that is stuck. You run it under hot water and the lid expands, loosening it. The brass from the casing can warp as well.

I would suggest keeping the gun in a lock box or some shaded area to minimize the exposure to heat.

Hope that this is helpful! If you have no other questions, please remember to complete a positive rating on your screen now so that we can close out the question.



Customer: replied 1 year ago.
Thanks Jim.
I am also interested in learning if the gun can trigger by itself as high temperatures may affect trigger mechanism?
In other words is it wise to keep a chambered s&w in the car? From the perspective of possible going off by itself
Expert:  ProShooter replied 1 year ago.

I cannot imagine that anything to do with high temperatures in the car could cause a firing pin to retract and go forward, striking a live round.

If you want to be 100% safe and sure, just unload the gun when its not in your immediate control.

Expert:  ProShooter replied 1 year ago.

Anything else?