Finding the mp3s is left as an exercise to the reader.
Medicine is way more complex than coding
It is? Most people in the modern world have some idea of what makes them sick and what to do to get better. Most people in the modern world don't have the first clue about software or what makes their computer crash. Attitudes like yours do nothing to demystify medical doctors' "illusion of omniscience".
The definitive source for Army terms is FM 1-02 Operational Terms and Graphics (where you can find the definition of "assault", for example). It does not contain "assault rifle", however its scope is operational rather than tactical, so largely does not deal with weapon nomenclature.