Hobbyist,
You will get almost nothing but negitive responses here about derringers. Filled mostly with opinions, and mostly not based on facts. Or based on experience with the really poor brands of derringers, not any of the good ones.
The American and Bond derringers are quality firearms. The American has been chambered in .30-30, 45-70, 223, 45 Win Mag,almost any caliber you can name, they would do it.
They both have excellent safetys and are quite drop safe.
Accuracy can leave a lot to be desired. Best I've been able to do with my American in 45 auto/auto rim is four rounds in about three inches at seven yards.
The large bores are not for the recoil sensitive. Very small grip. My 45 auto weighs one pound loaded. Will easily send a 260 grain bullet out the barrel at over 900 fps.
A derringer can have a place in the tool box. They are excellent as a 'get off me' gun. There are no accuracy worries in such a situation and the bullet and all the combustion gasses are directed into the enemies body if you've pressed the barrel up against him. They also won't jam in such a shot.
Very slow to reload and of course only two rounds.
Cat