Ballistic gelatin as a soft tissue simulant: A systematic review of applications, calibration methods, and synthetic...

Ballistic gelatin is widely recognized as the primary soft-tissue simulant in forensic and biomedical ballistics. However, variability in preparation, calibration, and reporting methods, along with growing interest in synthetic alternatives, has raised concerns about methodological comparability and scientific validity. This systematic review, following PRISMA-2020 guidelines, searched PubMed, Scopus, Web of Science, ScienceDirect, and Instituto de Defesa Nacional (IDN) databases for studies published from 2004 to 2025. Experimental studies utilizing gelatin or alternative soft-tissue simulants were included, whereas conference abstracts and purely numerical simulations were excluded. Sixty studies met the eligibility criteria and were evaluated for preparation methods, calibration procedures, aging conditions, testing protocols, and ballistic performance. Most studies used 10% or 20% Type A gelatin. Differences in bloom strength, concentration, mold geometry, temperature, and aging resulted in significant variation in penetration, yaw, and temporary cavities, limiting comparability. Few studies reported bullet ball calibration, though it is essential for verifying gelatin stiffness and for reliable comparisons. Synthetic simulants, such as SEBS elastomers and Clear Ballistics®, are easier to handle and more transparent, but often increase penetration, delay yaw, and pose calibration issues, limiting their forensic or medicolegal use. Properly formulated and calibrated 10% gelatin remains the best validated soft-tissue simulant for ballistic testing. Synthetic options show potential but do not yet consistently match real tissue in forensic or defense/wound ballistics work. Ongoing inconsistencies in preparation and reporting highlight the need for international standards in simulant design, calibration, and documentation to improve reproducibility and strengthen ballistic research.