mokster,
Ruger Blackhawks are EXCELLENT single action (SA) revolvers – outstanding quality, durable, accurate, reliable, with fine fit and finish – but in a defensive firefight, I doubt if any SA revolver can provide the rate of fire that you may require. I stipulate that many defensive scenarios are resolved just by showing a big handgun and others are finished with a single shot fired. However, what happens if you miss with the first shot against a felon armed with (for example) a 9x19mm semiautomatic loaded with 15+1 JHPs? I certainly would prefer a DA revolver or an autoloader under those circumstances!