Would there?
Or, more imnportantly, would those "self defense shootings" really matter or change the outcome?
The goal of any victim of a violent encounter is to survive, no? So if one has a violent encounter (such as an armed robbery, etc.) and loses nothing beyond their wallet, does the presence of an armed victim change the outcome relative to the stated goal? I grant you, it may get you one less robber (which would clearly be a good thing) but at what expense? Possibly an injured or dead victim, at the very least the victim's after-incident would be far more involved (i.e. dealing with legal questions, the press, possible arrest themselves, possible charges themselves vs. simply filing a report and going home).