When shooting targets with Forerunner while zoomed in, I had it repeatedly that my game froze. Can be that I was pressing the reload key while still being zoomed in after having shot something, I cannot remember, but the possibility exists. I think I was playing Gambit on those occasions (definitely when the last crash happened). At the last occasion, this happened while I was doing a sidearm kills bounty from the gunsmith (probably just completed it).