The objective of this work was to determine the reasons and to find the ways to prevent common mistakes in using conceptual and terminology framework in forensic medical ballistics. Basic research and dissertation papers, practice guidelines and textbooks, educational learning materials, as well as conceptual and terminology frameworks of the regulatory legal acts of the Russian Federation had been analyzed. The study outcomes make it possible for a forensic medical expert to use basic definitions and terms of forensic medical ballistics in his/her practice methodologically correctly and in a well-argued manner, to reduce dramatically or completely exclude a possibility of expert’s mistakes, to formulate reliable and sound conclusions upon the fact and conditions of a firearm use and upon a concrete mechanism of a gunshot wound formation in general.