Small pistols that allow thumbing the hammer

[Clusterfrack]

The Beretta APX allows you to block the firing pin your thumb; the FP block is on top of the slide and can be interrupted with your thumb while holstering. You lose this ability when you mount a dot.

I can't figure out how this works. Is it not the pinhole in the slide plate?

[jetfire]

I can't figure out how this works. Is it not the pinhole in the slide plate?

Top of the slide, just forward of the rear sight is the firing pin block. That moves up when the trigger is pressed, so thumbing over it allows you to feel pressure if the trigger starts moving to the rear.