There is a news story out this week, (The end of April, 2019) about a school resource officer's weapon discharging while in his holster.

In my experience as a gun owner and hunter, it's hard for me to imagine a situation where a gun spontaneously discharges. I know that slam-fire and drops can cause a discharge, but I'm talking about a holstered firearm or an otherwise resting one.

Does anyone have any information or statistics about how this happens? (In the general sense, not the specific case I mentioned. That's off topic here)

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    Note that the older the firearm is the less likely its safety mechanisms are as reliable, and possibly less likely that it even has safety mechanisms. So a firearm more than 100 years old is much less safe than a firearm manufactured today. Despite the importance of this, I leave as a comment rather than an answer since this does not apply to the general sense that you have asked for. But there is a large minority of people who still have and use antique firearms.
    – Loduwijk
    Commented May 1, 2019 at 21:44
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    I'm voting to close this question as off-topic because questions about random small arms are not about the outdoors. A hunting rifle would be on-topic.
    – user15958
    Commented May 2, 2019 at 7:15
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    I voted to keep open, I understand this is a complex issues. There is some history about the topic at the meta post Expand scope to welcome The Armory? Commented May 2, 2019 at 8:39
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    @JanDoggen That reasoning is ridiculous: You can't claim a general safety question about guns is not on topic because as an example, on off-topic situation was used, when you state yourself the question itself is relevant for many outdoors situation. As James mentioned, there could be a point about whether it should be on topic or not, but that's a way more general discussion.
    – imsodin
    Commented May 2, 2019 at 8:44
  • The term spontaneously is problematic. Of course everything depends on the type of system used in the handgun (striker VS hammer-fired, grip safety or trigger safety VS manual safety, etc.) but if a gun isn't cocked, there's virtually no way it will "spontaneously" fire. But a cocked gun could potentially spontaneously fire in certain conditions.
    – Gabriel
    Commented May 2, 2019 at 13:35

4 Answers 4


No, a gun will not spontaneously discharge It's an object that won't do anything without external input. A better term for this is negligent discharge because the human was negligent and messed up and cause the gun to go off.

There are all sorts of ways of causing a negligent discharge,

  • Assuming the gun is unloaded and pulling the trigger.
  • Assuming the safety is on and/or works and pulling the trigger.
  • Some guns are not drop safe, dropping them will cause the hammer to hit the primer.
  • Dropping the gun, going to catch it and pulling the trigger in the process.
  • Catching the trigger on your pants when reholstering.
  • Pulling the gun towards you by the barrel and the trigger catches on something.
  • Unholstering a gun and pulling the trigger while doing so.
  • Improper holster that doesn't cover the trigger and then an external object pulling it.
  • Keeping your finger on the trigger when you are not ready to shoot and then tensing.
  • Grabbing the gun out of a case and you pull the trigger while doing so.
  • Cooking off, if a gun gets hot enough it will cause the ammo to go off, can happen in housefires (which is why you don't want to store ammo and a gun in the same safe).
  • Slamfires where the action loads another round and fires it off, seen most often in old SKS rifles and in the S&W 15-22 before they fixed it.

All of the above are why it's important to observe the gun safety rules.

  1. Always treat every firearm as though it is loaded.
  2. Always keep the muzzle pointed in a safe direction.
  3. Keep your finger outside the trigger guard until ready to shoot.
  4. Always be sure of your target and what is in front of it and behind it.


I am having a hard time finding non biased sources on how many per year, but the one source I did find shows them on the downward trend and a small fraction of gun incidents.

  • When you refer to "not drop safe" how hard a knock would be required to make the hammer hit the primer? I ask as someone who's never handled a handgun, only a shotgun and only a couple of times - but was well drilled in the safety rules.
    – Chris H
    Commented May 1, 2019 at 21:34
  • @ChrisH I think its only like waist high onto a hard surface, but most if not all modern handguns are set so that there is now way for the firing pin to contact the primer without pulling the trigger Commented May 1, 2019 at 21:42
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    @ChrisH 100 years ago when the first Colt 1911 were made, they all had grip safeties which helps prevent the gun firing without a hand wrapped around the grip. The mechanism physically blocks the trigger from moving.
    – Gabriel
    Commented May 2, 2019 at 13:45
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    While I agree with the general sentiment of your post, the absolute statements are not true. Guns are mechanical devices and they can have defects that despite the owner's best efforts result in accidental discharge. The frequency of said events is extremely low but it's not 0 unless you jump through a lot of mental hoops to rationalize everything as negligent. Commented May 4, 2019 at 1:33
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    As far as house fires are concerned, there is no need to store ammo and guns in separate safes, so long as the guns don't have a round chambered. Why does it matter if the ammo cooks off in the same safe or in another? As long as it's not within the chamber, it will be just as destructive either way.
    – Ryan_L
    Commented Jan 2, 2020 at 0:08

About the only way I could imagine a firearm discharging on its own accord would be some kind of failure in the primer/powder that caused a spontaneous combustion. Perhaps some kind of large electric current perhaps or getting too hot.

While Charlie has listed many negligent discharge (ND) causes, I would actually classify this one as an accidental discharge (AD) since from what is known as this point a human was not handling the firearm at the time of discharge, which would point to a mechanical failure. Since it apparently went off when the deputy leaned against a wall (I assume on his strong side), either the holster failed, somehow activating the trigger, or the sear slipped, some internal part broke, etc. allowing the firing pin to hit the primer. I find either one extremely unlikely since there are multiple safety features built in to striker-fired firearms so it will be interesting to see what they determine as the root cause. It would be nice to see video as well to verify he hadn't recently "adjusted" anything.

As an anecdote to add on to imsodin's answer, you never trust the safety and always follow the safety rules. Local gun shop had an AD from a customer bolt-action rifle that was brought in loaded (unknowingly of course :/ ) . It was on safety, but turns out that model was on recall for the safety. When employee disengaged the safety to check the chamber to verify its supposed "unloaded" status, the .270 fired.

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    There was a news update today, 10/16/2019 that the officer in question had a "bad habit of fidgeting with his gun" The Pasco Sheriff's office said a student told them he had seen the officer manipulate the gun up and down out of it's holster before. The officer has been terminated for this incident.
    – TecBrat
    Commented Oct 16, 2019 at 18:23
  • @TecBrat Nice. Thanks for the update.
    – topshot
    Commented Oct 17, 2019 at 19:18

Yes, at least you should consider it to.

Rules (not exhaustive at all) that I was taught to obey at all times (and afaik that's generally a mantra of the "weapons-community" around here):

  1. Every weapon is to be considered charged at all times.
  2. Never point your weapon at anything unless you want to shoot at it.

For these rules to make any sense, shit (e.g. unplanned discharge) must be able to happen, which is also postulated by Murphy. Discharging while resting qualifies as (dangerous) shit, so you should consider it possible to happen.

That's also the reason why weapons are always deponated facing in a direction, where shooting would do least damage, why your rifle should always point to the ground while carrying, ...

This answer is based on the limited weapons experience of +-21 weeks of obligatory military service and heavily biased towards erring on the safe side, and in addition only targets the title question, not so much the body, but I believe it still has some merit. For a detailed answer, refer e.g. to the one by Charlie. Lets see if it survives the QA process :)

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    @CharlieBrumbaugh Scary o.O And an example why I hold on to my statement: Moving the selector triggering firing might not qualify as firing spontaneously at rest, but it definitely is totally unexpected and not the users fault. Better safe than sorry.
    – imsodin
    Commented May 3, 2019 at 5:55

No for quality guns, possible for poor quality ones. Here's a video of a gun spontaneously firing when shaken. Notice in the 2nd half of the video that it can fire even with the safety on. Basically don't buy crappy guns such as Taurus pistols.

  • Could probably happen even to higher quality ones. I'd say the only way to be safe is to not have a cartridge already in chamber and only cock it up before firing I'd say. Otherwise you always have a chance of this happening( but then again, walking without your CCW chambered means you gonna spend extra seconds in sketchy situation and it might cost, at least that's what most self-defense articles like gunicorns.com say... So no real way around it...)
    – BrownT
    Commented Jul 19, 2023 at 9:50

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