Ammunition Failure Mystery

I recently went shooting with some friends and grabbed a Ruger Security 9 compact pro that I store in my car as a backup weapon. It was loaded with Critical Duty 9mm Ammo that was about 3 years old. The gun is stored pointed down in a holster and it had been a year since I cycled the Ammo. I was annoyed and later concerned to learn that every round resulted in a misfire. On further inspection, a light strike was present on each primer. I replaced the Ammo with junk I bought in bulk and experienced no problems the rest of the day.

I see four possible causes of the problem: temperature/ humidity, incompatible Ammo, vibration of the primer into the case, or problem with the firing pin. I tried the Ammo in two other identical pistols with one round firing. I shot identical ammo from the same lot that I store in a dark cool dry environment and had no problems. I would really like the problem to be vibration issues but welcome the opinions of others.

The problem remains: how do you stage or secure a pistol in your car and avoid causing problems with the Ammo?

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Hum, I would put my money on a primer that got fouled due to moisture.

I reload and there is no way, particularly for a factory round, a primer can come loose.
If it were the powder that had gone bad you would have had a pop and a squib rather than a bang.

Did you try replacing the ammo with non-junk ammo, more Critical Duty and try it with EDC ammo?


Unrelated to the ammo failure, the Sheriff’s Department runs ads about twice a year where I live reminding people that vehicles are not firearm storage lockers.


The moment illinois created gun free zones, they designated cars as firearm lockers.


Every state is different aren’t they :grinning: I live in Florida.

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I replaced all 15 “duds” with critical duty Ammo from the same lot number, that was stored in ideal conditions and they worked fine. The nylon tips were worn on the duds, but I can’t see how that could affect the primer strikes.

I found some interesting data in this article:

Damaged by Conditions

Ammunition can become contaminated. The most common culprit is light penetrating oil. Oil is an extremely effective desensitizer of primers. That’s the biggest reason why most ammunition has lacquer-sealed primers. Moisture can also damage primers, but moisture is not nearly as likely as light penetrating oil to actually penetrate into the primer. Brief exposure to moisture in the field is normally well tolerated by ammunition. Long-term exposure such as storage in damp conditions can destroy ammunition"

Since it was all rounds in the chamber plus magazine, I think oil is ruled out as a suspect.

Not the issue you had, but I found this tidbit interesting as well:

If the primer is hit once and it does not go off due to insufficient firing-pin force, the sensitivity is further decreased … Hitting it again doesn’t prove anything either way.


@Loren_Jay, was the ammo sitting 3 years in the handgun in the car?

Ammo was in handgun for about one year. The previous two years it was stored in a cool dark dry environment.

Jerzy Helping Hand
November 8

@Loren_Jay, was the ammo sitting 3 years in the handgun in the car?

Hmm… interesting experience then.
I never keep ammo loaded in firearm longer than 5 - 6 months, so hard to tell what could cause your issue.
Perhaps it was the sum of vaporated handgun oil and car’s vibration?
Anyway this example proves it’s a good habit to not to store SD ammo at the firearm for a long time.


I’d also guess moisture or oil. Also have a vehicle weapon. Years ago I learned to remove mag ( & the 1 in the tube) hold it bullet end up & shake it. Also shake boxes of ammo before use. old habit. Always run a couple of rds twice a year. Minimum


The temperatures have cycled between 20 degrees Fahrenheit and 130 degrees Fahrenheit depending upon time of year. I’m not sure if the primers detonated. They had mild indentations. One fired later in a different gun but the rest would not fire. Could the powder become moist and packed anteriorly, preventing spark from igniting powder without causing a squib?

Clearly, I can’t leave the Ammo in the car for a year. I’m just trying to figure out what went wrong. Science thang. I suppose I should take an inirtia bullet extractor to a few of the rounds, remove the primers, abs I spect the powder and primers.

I was going to suggest pulling the bullets. You got to it first. Let us know what you find. See if moisture did find its way in. Interesting nonetheless.

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Although I can’t gaurantee that the following is the issue, I might assume it is possibly the cause…

I lived in IL, MN, and WI. Two things that I used to do that caused some tools to form rust spots (even a 420HC blade) was 1. I used to open my windows a lot to save on utility bills in the Spring and Fall (high story apartment), and 2. I used to keep some landscaping tools in my car which was parked outside year round.

When the metal gets cold and is subject to a warm environment, e.g. stored at night in the 40’s and days getting into the high 60’s, the cold metal condenses water from the air. It’s like when you are working outside in the winter with glasses and you walk into the house or store and your glasses fog up. This condensation sits on the surface for awhile, and can happen day after day, week after week, etc.

I can only assume that over time, this caused reliability issues with your ammo, or even possibly rust somewhere in the firearm (I would check your striker, channel and spring for any signs). It is further complicated with car lock boxes that usually come with holes in the side to tether them to the frame of the vehicle.

Although it might reduce rapid acces to your firearm, you might think about placing it in a ziplock bag with some desiccant in it, all inside of the lock box. Or, if you have a brifecase or backpack, you can just put the lockbox with firearm in your backpack while in the car and bring it inside everyday without having to fumble with taking it out of the lockbox. My suggestion is to not leave it in the car overnight or for long periods where the vehicle is not readily accessible by you.


You’d 100% know it, you’d have a squib round you’d have to get out of the barrel.
Plus you for sure would have heard it.


I did a little reading about lead styphnate aka lead(2+);2,4,6-trinitrobenzene-1,3-diolate:

It has a melting point of 235°C. I don’t think my car could get above 455°F without showing some damage.

It is practically insoluble in most organic solvents

Akhavan J; Kirk-Othmer Encyclopedia ofChemical Technology. (2004). New York, NY:John Wiley & Sons; Explosives and Propellants.Online Posting Date: September 17, 2004.

Practically insoluble in water

Akhavan J; Kirk-Othmer Encyclopedia ofChemical Technology. (2004). New York, NY:John Wiley & Sons; Explosives and Propellants.Online Posting Date: September 17, 2004.

I’m leaning back toward a mechanical issue with the light pin strike mark on the primers. Maybe there is a mechanical problem with the pistol from vibrating in the car with hammer cocked?

It’s frustrating, because I cannot figure out how to reproduce the problem.

Loren Jay Chassels, DO, MST

Fizbin USCCA Certified Instructor
November 9


I’m not sure if the primers detonated.

You’d 100% know it, you’d have a squib round you’d have to get out of the barrel.
Plus you for sure would have heard it.

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This might help:

Heat itself isn’t that destructive, but fluctuations may cause humidity and condensation. Think about when glasses or cameras fog up going from an air-conditioned home to a hot backyard. You don’t want your ammunition supply to be subjected to these highs and lows. Moisture will attack gun powder.

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Excellent article about ammo storage. Thank you for the reference. I will make sure to cycle my ammo more frequently by using the “expensive” rounds that I keep in my staged defensive weapons.

This would be my contention since you noted previously that there were light strikes on the first go around. That the gun was cocked for a year SHOULD have no bearing at all as springs wear out through cycling not with being compressed or uncompressed. That said have you taken apart the gun and inspected and cleaned the top half? I am constantly amazed at how much dust and dirt things in a glove box pick up if it’s never opened.

You essentially have two culprits, the gun and the ammo. If the gun worked with new ammo then it stands to reason it is the ammo. Condensation would be my leading guess as noted above. Second to that would be repeated vibration but that is suspect otherwise we would be hearing about FTF from police across the country as I know police that have had the same duty rounds in their guns for literally YEARS. This is quite a mystery.



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Well this has me curious about the two mags in my trunk loaded with HSTs for probably six months. They’re kept in an waterproof ammo box along with a spare box or two of everything I shoot for when I’m at the range and having more fun than I expected when I leave the house.

One thought I had about the OP’s problem, perhaps the firing pin or striker channel was somehow gummed up from being in the trunk. Most oils tend to evaporate over time and turn into goo or shellac. Doesn’t explain why the rounds from the house fired when the trunk stash didn’t unless firing somehow loosened up a sticky firing pin or striker.

Striker fired guns, by the way, should always be dry after cleaning, not oiled.

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