There is one thing I just can't shake. This "palming a derringer" deal keeps looking to me like a good way to blow off a finger if it's cocked. If it's not cocked, I fail to see the point.
I was wondering the same thing. So I decided to try a couple ways to see what I've apparently been missing.
I don't own a derringer but since Quatin had also recommended a NAA in .22 magnum for the same role, I decided to use that.
"palming" it the way he described (fingers totally enclosing the gun,) it took me 1.5-2.5 seconds to cock it and pull the trigger. These times are estimates only.
Then I cocked it and held it so that my ring finger secured the butt while my trigger finger was alongside the barrel. This hold obscured the gun for the most part and might comply with the unobtrusive element that supposedly makes this such a dynamite idea, but the other guy would have to not be paying any attention at all.
From that grip, I could pull the trigger with my middle finger much quicker, but I noticed my index finger was still alongside the barrel. This raised two concerns: 1) the finger may extend past the muzzle, regardless of barrel length. Mine is the longer one and was mostly not an issue. 2). The index finger is covering the flashgap.
So I brought the index finger over the top of the gun so it poked out between the index and middle finger. That worked pretty well....for one shot. There was no way to cock the gun again holding that way. I'd say these times were right at one second. I do not believe that quatin can approach anything close to .4 holding it as he described.
I considered trying this at the range with ammo and getting some hard data like actual times and hits, but quickly realized just how asinine that pursuit would be. I won't risk my fingers (at best) to prove just how stupid an obviously stupid technique really is.
But maybe I'm doing it all wrong. Perhaps quatin can post some pics or video detailing the proper technique.