I (like many) carry a Glock or a revolver. Pull it and shoot. No safety. No cocking. I can be on target in 1/10 of a second if the target is low and close like a dog.
I'm a Glock'aholic!

No empty chamber, external gun safeties, etc. My safety is between my ears with safe gun handling, not some lever, button, or other implements to keep someone with poor discipline from shooting themself or someone they love.
I was drinking my coffee this morning and thought what I heard outside was a vehicle hitting something (I'm 1200' from the public road). What I found on my front porch as I opened the door were two dogs who both got two rounds as fast I could pull the trigger. I closed the door and came back a few minutes later to make sure they were humanely put down since the fight was totally gone in one and the other was still trying to bite me but, couldn't move well. Total time of recognition of the threat to closing the door after firing was seconds with actual firing being ~3 seconds. Threat recognition seemed slow to realize but, engagement was really fast.
The Frontsite shoot-house training apparently working in this instance as there was no real planning or preparation other than grabbing the pistol by the door as I opened the door to investigate the noise I heard.
These two dogs appear to be the ones chasing cattle on my front pasture. Turns out, the noise I heard was them trying to kill my two cats.