3D-Printed PLA Projectiles: What Did Testing Reveal?

Testing the reliability of 3D-printed parts matters most when a proposed application involves high forces and serious safety risks. A paper by Adi Pandžić, PhD examines FDM-printed PLA projectiles in a limited experimental setting. The results provide preliminary research data, not instructions for manufacture or proof that such a product is safe.

Key findings

• The study examined a PLA projectile made using FDM, a process that builds objects by depositing material layer by layer.
• The experiment covered 16 projectiles across two phases; detailed penetration results were reported for five test samples.
• In the second phase, average measured penetration into a wooden target was 18 mm, with results from 12.8 mm to complete penetration of a 25.4 mm board.
• For the five test samples, the paper reports an average velocity of 254.6 m/s and a standard deviation of 26.2 m/s.
• The paper notes that wood is non-uniform and that the small sample size does not support reliable prediction of performance.
• The study points to the need for standardized targets and larger, controlled tests; it does not establish that the process is safe for practical use.

Why test 3D-printed materials?

Additive manufacturing can produce prototypes and components quickly without the tooling used for conventional mass production. FDM is widely accessible because it uses thermoplastic filament and relatively simple equipment. PLA prints are consequently common in education, product development and early-stage material experiments. But access to a process does not mean every printed part will behave predictably or suit a safety-critical application.

For parts exposed to sudden loads, relevant factors include geometry, internal structure, layer bonding and variation from one print to another. Infill means the material structure inside a printed part’s outer walls. Testing such samples therefore requires carefully defined procedures and qualified oversight. This paper’s subject makes that need especially clear: it concerns projectiles and live ammunition. The results should be read as a report of an experiment, not as practical instructions.

What the study examined

The study tested a projectile made from PLA filament using a desktop FDM printer. FDM, or fused deposition modeling, forms an object by depositing successive layers of material. The experiment recorded whether the projectiles passed through the firing phase without visible damage in the reported test, how they behaved against a wooden target, and the measured penetration depth. The paper reports 16 projectiles in total across two phases.

The first phase focused on basic observations of system function, while the second measured velocity and penetration. The target in the second phase was a fir board 25.4 mm thick, placed 3 m away. A chronograph measured velocity. The penetration table presents five test samples, while the experimental group also included reference shots. This overview deliberately stays at the level needed to understand the research: construction and adjustment details are not necessary for interpreting the study’s findings and limitations.

Results and how to interpret them

The reported penetration depths for the five test samples were 16.0 mm, 12.8 mm, 25.4 mm, 20.0 mm and 15.8 mm. One result was recorded as complete penetration through the board. The average was 18 mm, and the difference between the lowest and highest recorded values was 12.6 mm. The results associate the spread with the non-uniformity of wood and differences among individual printed samples.

The paper gives an average velocity of 254.6 m/s, a spread of 55.8 m/s and a standard deviation of 26.2 m/s. These figures describe this experiment alone; they should not be treated as reliable predictions for other prints, materials or conditions. The paper also reports that the sample with the highest measured velocity did not achieve the greatest penetration. This illustrates why a single parameter, such as velocity, cannot by itself explain an impact result.

Wood is not a homogeneous target. Its structure and the precise impact location can affect measurements, so the recorded depth is not a universal measure of material performance. In particular, penetration into a wooden board cannot by itself predict injury or outcomes in human tissue. The study does not establish a safe, non-lethal or medically predictable application.

What the findings mean for engineers and students

For engineers and designers, the paper is a reminder that one successful test is not the same as a validated product. Safety-critical applications require evidence about repeatability, variation, behavior under different conditions and safety margins. Testing only a few samples against wood cannot support those conclusions. The same principle applies to other 3D-printed parts: the properties of one sample should not automatically be assumed to represent a whole production run.

Students can use the paper to see how experimental outcomes depend on target selection and sample size. A standardized test medium helps researchers compare results across studies, while more samples provide a better view of manufacturing variation. In additive manufacturing education, the paper also prompts an important distinction: demonstrating that something can work in a single test is not the same as showing that it works reliably.

Limitations and next steps

The main limitation is the wooden target, whose non-uniform structure makes comparison and modeling difficult. The number of samples with detailed penetration results is also small. The paper proposes future work using more homogeneous, standardized targets, better control of test conditions, advanced measurement systems and larger sample sizes. Any such work would require appropriate professional, legal and safety controls.

Conclusion

“Evaluation of Firing Reliability and Penetration Depth of 3D Printed PLA Projectiles for 9 X 19 mm Ammunition” appeared in 2025 in the Proceedings of the 36th DAAAM International Symposium on Intelligent Manufacturing and Automation. Its contribution is a set of preliminary experimental observations about FDM-printed PLA in a highly sensitive context. Average penetration of 18 mm in wood, alongside substantial variation between results, shows why more standardized evidence is needed. The findings should be interpreted cautiously: they do not establish safety, reliability or suitability for practical use.

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Author: Adi Pandžić, PhD in Mechanical Engineering

This article summarises a published research paper; please refer to and cite the original paper. About the author

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