Gun Jams – The Challenge for Every Gunsmith

Gun Jams – The Challenge for Every Gunsmith

Gun safety teaches the mindset and habits necessary to prevent unintentional injury, illness or death. A common method for practicing safe firearm handling is routine gun maintenance. Maintenance helps combat gun jams, a frequent issue for many firearm enthusiasts. It is for this reason that this month’s discussion will be about gun jams and how to prevent them. In my experience and research, I have determined there six reasons why guns jam:

Dirty Firearm

In my opinion, the single most common reason for malfunctions is a dirty firearm. As a gunsmith, I have fixed most jamming issues by simply cleaning the weapon. Many semi-automatic shotguns and rifles operate by using a gas system. Gas system firearms generate a lot of carbon which clogs up gas ports, gas pistons and springs. Pistols however, get gummed up from powder and can keep the firing pin from striking the primer hard enough. Extractors can also fail when the firearm isn’t cleaned like it should be. I recommend purchasing an iron tank or stainless steel tank from Brownells with a burner tube, tank stand, and some Dicro 909.  You can connect it to a simple propane tank, after you make a short trip to the hardware store for some common gas fittings.

Dicro 909 is a powdered soap you mix with water. Once heated up, drop your firearms in it for 20 minutes or so. I recommend getting some thick heat resistant rubber gloves. You will need to scrub the firearm with a gun brush. You will want to use soft bristles that will not scratch the firearm—you will be amazed at how clean it will get. I have one word of caution when using hot water to clean the guns: be sure that you are aware of any gun parts that are heat sensitive. Many hydro-dipped shotguns and rifles can’t handle hot water and their camo dip will come off. You can always clean firearms using approved gun cleaning chemicals or ultra-sonic cleaners.

It is still a mystery to me why gun owners don’t clean their firearms. A clean weapon is a well-functioning weapon, and maintenance is pinnacle.

Lubrication Issues

Another item that contributes to malfunctions is lubrication issues. Lack of lubrication, or too much lubrication, will make a firearm operate incorrectly. Lack of approved gun oil will cause parts to wear incorrectly or even cause them to break. I encourage you to research the firearm you are working on. If it is a newer firearm, manufacturers provide lubrication details on their websites or owner’s manuals. For older guns, some research and common sense will go a long way. Many think the more lube the better, however, too much lubrication picks up dirt, dust, or other foreign matter. I’ve received rifles in my shop that have been packed full of wheel bearing grease.

A good rule of thumb for lubrication is to only oil the metal-to-metal contact points. Only one or two drops of oil is all that is needed.

Ammunition Issues

A third item that contributes to malfunctions is ammunition selection. There are hundreds of ammunition manufacturers in the world. Some manufacturers do not use the best powder, bullets, and primers on the market. While some rifles, shotguns, and pistols really don’t care what type of ammo you use, others are finicky. Take the Beretta A300 shotgun for example. The A300 is a premier firearm—it is probably one of the most versatile shotguns in Beretta’s offerings. Countless Beretta owners have been frustrated with their shotgun because it won’t cycle low brass shells.

Low brass shells have less powder in them, so they have less force and gases to cycle the shotgun correctly. Searching on their website, nothing is stated about low brass versus high brass shells. While speaking with their customer service team, they stated that the shotgun needed to shoot at least 500 to 1000 rounds of high brass shells before using low brass shells. Essentially, they state that you need to break the shotgun in.

Manufacturing Defects

Defective guns happen, and defective parts are usually the cause. Today’s firearms are made on an assembly line. Many hands touch a gun before it leaves the factory. Inevitably, parts will be installed that don’t meet the specification. Parts may have burs, manufacture defects, wrong springs installation, or a host of other issues that can happen during manufacturing process. As a gunsmith, it is your job to inspect those parts to make sure they function as they were designed. It’s always a good idea to look for recalls on the firearm before you crack open a rifle and ruin the chance for the manufacturer to fix or replace the problem for free. Working on a firearm with a recall could void the customer’s warranty.

Researching the internet and publications will help you discover if the problem they are having has been documented. Doing your research will save you a lot of time trying to figure out what the issue is and how to solve it. I have even contacted other gunsmiths to get their thoughts on an issue. Gunsmiths are usually a tight group of folks and are usually willing to share their knowledge.

Improper Weapon Handling

There are many different terms for improper weapon handling. Limp-wristing is a common reason for a gun malfunction. Limp-wristing is when shooter doesn’t hold the firearm firm enough. It is mostly seen in semi-automatic pistols, semi-automatic shotguns, as well as rifles. All firearms need to be held firmly when fired. If a pistol is not held firmly, its blowback inertia will not eject the round correctly. Shotguns also rely on that blow-back inertia to eject the fired shells. When the casings or shells are not ejected, the firearm industry calls this failure to eject (FTE). There are many types of FTE, and one example of this is called stove piping. Stove piping is when the spent casing is not completely ejected from the weapon and gets trapped in the firearm.

Sometimes when you have a FTE, you will in turn have a failure to feed (FTF). If the old casing is in the way of the new round, it has no place to go. Determining if your customer is holding the weapon improperly can be a touchy subject to bring up. I see improper weapon handling mostly in older gun owners. When a gun owner loses strength in their fingers and hands they usually don’t realize it. It’s hard to tell an older customer who has been shooting their entire life that the gun they are shooting with may not be the best fit for them anymore, but this is a gunsmith’s responsibility.

Magazine Issues

Lastly, I will talk about magazines. Magazines for pistols and rifles that are shipped with the firearm usually work well. Aftermarket magazines can also work well, but be weary of what you purchase. You should do research to make sure you are getting a quality magazine. Reviews are often helpful to guide your purchase. Many magazine issues or failure to feed issues I encounter are a result of customers not rotating the rounds in their magazines. You have to unload the magazines and reload them monthly to keep the magazine spring from being compressed too long. Compression fatigue of the magazine spring weakens the spring. Sometimes the gun they are having trouble with is the one that has been in a conceal carry holster, beside the bed, or in the car as a personal protection piece. You don’t want the weapon to fail when you find yourself in a self-defense situation.

In conclusion, these are the most common items that can cause firearm jams. You will find as you progress in your gunsmith career, that there are many tricks and modifications that can be done to improve a firearm’s functionality.

Semper Fi


By: David Johnson, Leatherneck Gunsmithing

Gun Jams – The Challenge for Every Gunsmith