Question

why are hollow point rounds banned in the geneva convention, and not FMJ?

Answer 1

hollow point rounds are designed to spread out on impact causing extreme damage to everything around it. A 357 hollow point can literally split a head open. FMJ is pretty much the opposite, it has a limited area where it can expand. FMJ is seen as "more humane." FMJ also has a much larger stopping power, which increases its effectiveness to put an enemy combatant down