I downloaded the game, started it up, let it download the correct form of DirectX upon my first startup, matched the resolution to that of my monitor, set the rest of the settings to as low as possible to increase FPS from 19 to 50 as minimums, entered either the infantry showcase, editor, or first firing range challenge, fired all different weapons repeatedly, and did not hear the sound of my weapon going off. Note that I don't know of anyone else having this issue, but this is the process that I went through when playing the game. I can reproduce this every time I start up the game, but to my knowledge, no one else can.