Can A Handgun Backfire? What You Should Know

can a handgun backfire

There is nothing like the excitement of slowly squeezing the trigger of your handgun and feeling the rush of adrenaline as you take each shot.  As an avid gun owner and firearm collector of many years, I am frequently approached by prospective gun owners regarding their safety concerns. One of the most commonly asked questions relates to a possible backfire from handguns. Is it really possible for a handgun to backfire? Here’s what you should know.

It is impossible for a handgun to shoot an entire bullet out the back. If a handgun malfunctions, it could suddenly expel hot gasses or small shrapnel bits out of the back of the handgun, but it could never actually fire an entire bullet backward. 

That is not to say that you should relax. You must be aware of possible accidents that can occur when firing your handgun. It is essential to know what could cause a handgun to malfunction to avoid injuries and keep your firearm in perfect working condition.  

How do handguns backfire?

When you pull the trigger of a handgun, the gunpowder inside the bullet is ignited, which causes a small explosion inside the gun’s chamber. There is a sudden build-up of pressure in the gun’s chamber, which releases as the bullet, and the fumes, exit through the barrel.  The pressure forces the bullet head to be propelled at high speed out through the gun’s barrel. If there is some obstruction, the gasses released during firing would need to find some other way out of the firearm. This phenomenon is sometimes referred to as ‘backfire.’ 

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Why do handguns backfire?

There are two major types of malfunction which could occur and could cause hot gasses to shoot out the back of the firearm. Cartridge malfunctions refer to faults with the bullets, and mechanical malfunctions are related to problems with the handgun itself.

Cartridge Malfunctions Mechanical Malfunctions
Case head separation – Most cartridge cases are made from a brass alloy that stretches when a shot is fired, and there is pressure build-up in the cartridge chamber. Should the firearm’s head spacing be too long for the cartridge, the case can split due to the cartridge case stretching excessively. 
Metal fatigue – With any explosion, pressure needs to release from the enclosed space as quickly as possible. Suppose the metal of a handgun has any cracks or damaged areas as a result of metal fatigue. In that case, the explosive action caused by the ignition of the gunpowder inside the bullet may exit the gun through one of these flaws instead of out the barrel. 
Pierced primer – This is when the firing pin pierces a hole through the primer of the cartridge.  The primer is only designed to be struck, not pierced. This faulty action causes the gunpowder to ignite and expel from the rear of the cartridge instead of propelling the bullet head out of the gun’s barrel. 
Worn ‘Sear’ – This critical part of the firearm holds the hammer and pin back before the trigger is pulled. If this mechanism is faulty or worn, it may not hold the handgun mechanism in place, and the gun may fire unexpectedly or expel some backfire gasses from the back of the handgun. 
Squib load – This is when a fired bullet cannot entirely leave a gun’s barrel. The shot that follows will encounter the obstruction inside the barrel that may cause it to backfire or burst the gun’s barrel.
Slamfire – This malfunction could happen during the process of loading a bullet. If, for some reason, the bullet ignites before the chamber is fully sealed, the gun could backfire.
Too much gunpowder – Each type of gun requires specific ammunition. Bullets should never contain more gunpowder than is specified. Any upward deviance from the recommended amount may cause a backfire action from the handgun. 
Out of Battery Ignition – When a firearm is discharged, the mechanism should immediately spring back into place and be ready to shoot the next bullet. If another shot is fired before the gun mechanism is back in position, it could cause the handgun to backfire.

Can a dirty handgun explode?

A build-up of dirt in a handgun can cause a gun to malfunction but not necessarily explode.  Corrosion can also have the same effect. Any factor that may hinder the bullet from fully exiting the firearm could cause problems.  If this happens, the next time the gun is fired, the exiting bullet can become obstructed by the remains of the previous one. This causes the exploding gunpowder to be trapped inside the firearm, and hot gasses may be expelled from the back of the handgun.

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How to prevent handgun backfire

While it is extremely rare for a handgun to backfire in any way, there are some tips that you can follow to ensure that your firearm performs safely and reliably every time you use it.

  1. Check that the barrel is free of all obstructions before you use it. 

Most firearm malfunctions are a result of human error. In some cases, owners clean their firearms and forget to remove the cleaning cloth or store the gun with the cleaning ramrod and cloth inside. This obstructs the bullet as it is propelled forward and may cause the fumes from the exploding gunpowder to be propelled out the back of the gun.

  1.  Always load the correct ammo into the specific firearm model.

There are some instances where bullets of different calibers fit into other models of handguns. An example of this is the bullets of a 357 Magnum and a .38 Special. Both of these types of bullets could fit into the same handgun, but the result of doing so would be disastrous. 

  1. Keep your handgun in good working order.

This sounds obvious, but gun owners should get into the habit of doing a visual and mechanical inspection of all parts of their handgun before using it. They should check for any sign of cracks or metal fatigue that may prevent the gun from operating correctly.

  1. Check for rust!

Like all metal objects, guns rust. As guns age, the metal oxidizes and causes corrosion. While the handgun may look in mint condition on the outside, an inspection must always be made of the inside of the barrel to ensure that it is completely clear of rust build-up. The bullet must be able to shoot down the barrel smoothly without encountering any rust debris inside the barrel. 

  1. Ammunition must be in good condition

Using old ammunition can be a recipe for disaster. Cartridges degrade over time, and care must be taken to check ammo before it is loaded.  There must be no wear and tear of the casing. Old ammo could explode incorrectly and cause gasses to escape out of the back of the gun.

  1. Check where your ammo was made

If you are making bullets or purchasing from a private supplier, check the specifications used when manufacturing the cartridges. If too much gunpowder was used, the explosion created by the firing pin may be too great for the chamber, which would cause the expulsion of hot gas from other parts of the gun.

  1. Ammunition must be dry

Moisture on any part of your handgun should be prevented at all times. Specific care should be taken to ensure that bullets are clean and dry before they are loaded. If the gunpowder inside the bullet gets damp, it may not ignite as expected when the trigger is pulled. Any moisture could either cause a delay in firing or some other malfunction within the chamber. 

  1. Check the temperature of your ammunition

If your ammunition feels hot to the touch, do NOT load it into your handgun. Keeping ammunition in a glove box of a hot car, or even worse, on the dashboard of your truck, should be avoided at all costs. Excessive heat increases the burn rate of the propellant, which in turn increases the pressure generated when the gunpowder is ignited. It can lead to the weapon failing catastrophically. 

  1. Use the appropriate gun cleaning equipment

To keep your handgun in tip-top condition and ensure that it never backfires, it is important to use the correct cleaning materials as supplied by a gun shop. Your firearm must never be cleaned with household cleaning agents. There are several popular brands to select from, such as Hoppe’s, Breakfree, Sage, and Ballistol, most of which are available as complete cleaning kits to keep your handgun in perfect working condition.


It is not possible for a handgun to ‘backfire’ an actual entire bullet towards the shooter. There is, however, a possibility that it could malfunction and cause injury to the person firing it or those standing close by, by expelling hot gasses or shrapnel out of the rear of the gun. Gun owners have the responsibility to ensure that their equipment is always in excellent condition so that unpleasant incidents of this type do not occur, and they can always enjoy the experience of using their handguns.