After Kyle Rittenhouse shook his head and said, "No, I don't think so," the Judge, Bruce Schroeder, interjected and asked the Prosecutor, Thomas Binger, to clarify "expand" or "explode."
After that, Prosecutor Binger rephrased his question and asked Kyle Rittenhouse what "a hollow point bullet would do if it were shot…at a deer?"
The Prosecutor's statement on ammunition came after Kyle Rittenhouse had already verified that his AR-15 used full metal jacket (FMJ) bullets, not hollow points bullets.
Because of the Prosecutor's firearm ignorance or understanding of firearms or firearm bullets, he ended up embarrassing himself.
He started talking about something he knew nothing about, which is why inevitably he ended up doing the one thing they tell you as a trial attorney never to do; never ask a question you don't know the answer to!