If I have the opportunity to get into a prone position or have something else I can use for support, I could make 50 yard pistol shots under stress. Most of these situations are painfully slow and deliberate according to witnesses, so having the time to get into a good position to snipe them isn't that far fetched. Given that my mobility is limited, going prone is probably a good move for me if I choose to engage from distance anyway. I believe that I would try, but we'll never know until the need arises.
If the threat is moving, it depends on how fast and what direction relative to me.
If the threat is moving, it depends on how fast and what direction relative to me.