Are 3D Printed Lowers Safe? All You Should Know!

A lower receiver is the most important part of a firearm. It is, at least in terms of US law, the definitive part that makes a gun classifiable as a firearm. But what would happen if you made your own firearm with a 3D printer? Would it work and more importantly how safe would it be for you the user?

Newer 3D printed lowers are more functional and safer than the first 3D printed lowers. Thanks in part to better materials and consistent iteration, lowers are becoming much safer to use and their performance is improving.

This has not always been the case, however. The first 3D printed guns were unsafe and had abysmal performance. But 3D printing continues to improve, and nowhere is this more apparent than in the space of using printers to develop complex items like prosthetics and of course firearms. 

Today we want to explore just how far 3D printing has come by looking at the technical capabilities of 3D printed items like lower receivers. If you’re curious as to what is possible with a 3D printed firearm then keep reading to find out.

On a side note! If you’re looking for a reliable and high-quality 3D printer, we highly recommend the Official Creality Ender 3 V2 Upgraded 3D Printer (Amazon Link).

This printer is an upgraded version of the popular Ender 3 model, with a range of new features and improvements that make it even easier and more convenient to use.

The Ender 3 V2 is an excellent choice for beginners, kids, and experienced users.


Are 3D Printed Lowers Any Good?

Modern 3D printed lowers have an improved performance range. Technical and material advancements in 3D printing have made it possible to design and fabricate a lower that can better handle the heat and force stresses of a firearm. 

To fully understand the capabilities of a 3D printed lower, however we first have to understand what happens when you fire a gun and how that creates technical challenges for 3D printing a lower.

Aslo, we recommend that you check out our post Do 3D Printed Lowers & Silencers Work? How Reliable Are They!

What happens when a gun is fired?

Heat and force are generated when a gun is fired. The force generated in a gun is of course the recoil. When fired the recoil is strong enough to knock you off your feet, dislocate a shoulder or break a wrist. If the gun itself is made from brittle material it will highly likely explode. 

There’s also a tremendous amount of heat produced when a weapon is fired. The heat produced from a gun can be as much as 300 degrees Celsius. The high temperature from firing a weapon can cause heat cracks on a metal gun as the metal cools. This effect is even more pronounced on a gun made from plastic.

Heat and recoil make it necessary to use material that is force and heat resistant when manufacturing a gun. This is why most guns are made from material like high-carbon steel and not plastic. 

How Do Heat and Force Affect Plastic ?

3D printed parts are made from thermoplastics. These are plastics that can be molded into a shape when heated before solidifying when cooled. Different plastics melt at different temperatures. PLA, the most commonly used printing plastic, melts at between 180 to 230 degrees Celsius.

3D printed parts are anisotropic. This means they have a propensity to split along the build direction due to weak inter-layer bonding. Force, such as from firing a gun, is almost certain to cause the layers in a 3D printed lower to split. In other words, the lower will break when fired.

Heat and force are the primary technical obstacles in achieving a lower that can fire multiple rounds without failing. The first 3D printed guns like The Liberator for example, could only fire one round and were prone to exploding in the users hands. These were however, made from weaker materials like PLA.

Fortunately, materials have improved and with them the prospect of a 3D gun that can fire multiple rounds without failing. 

Are 3D Printed Gun Frames Safe?

3D printed gun frames have become safer to use due to the development of stronger printing material. Older gun frames were made from materials like PLA or ABS that did not have enough heat and force tolerance to safely fire a gun. Modern frames can employ stronger materials like PEEK or metal making them less likely to fail. 

3D printer materials differ in terms of their tensile strength, flexibility, heating temperature and durability. You can design and build a stronger part based on what material you use. In the early days of 3D printing guns, options were limited in terms of what material you could use. Now there are more than 25 different types of printing material to choose from. 

PEEK or polyether ether ketone is an industrial grade plastic used to make medical implants and aerospace components. It is possibly the most suited for printing gun frames because of its unique properties.

PEEK has a high melting point of around 335 degrees Celsius. It’s also both stronger and lighter than stainless steel. These characteristics make PEEK a prime material for printing a light weight gun frame with superior strength compared to most other materials. Source

Aside from PEEK, there are also metal filaments. These are filaments that are either plastic based with metal infused or 100 percent metal.

Are 3D Printed Items Safe?

3D printed items are generally safe for use. Safety largely depends on the intended application and the material the item is made from. For example, items made from ABS are not food safe due to the toxicity of ABS material.

Thermoplastic Elastomers (TPE) produce flexible 3D items. They are also a great alternative for making rubber products because they do not contain latex to which many people are allergic. Source

PETG is generally considered a food safe plastic. This means you can use PETG to print items like cups that will come into contact with food. 

Is 3D Printing Emissions Safe To Breathe?

3D printing produces Volatile Organic Carbon (VOC) and Ultra Fine Particles (UFP). These are toxic fumes that are harmful when breathed in. Printing should therefore be in a well ventilated area and care should be taken to avoid inhaling the fumes produced.

Not all 3D printing materials have the same level of toxicity. PLA produces lower levels of VOCs and UFPs which makes it a much safer filament to work with than ABS. PLA is made from organic material like cornstarch. This is why it has a lower toxicity than ABS which has a petroleum base. Source


I am a very well experienced techie civil engineer who's extensively interested in 3D printing technology and even more captivated by the potential of 3D printing livable structures

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