Besides my losing that finger, obviously?
This.
That uses a shotgun, I was thinking of a pistol/revolver. Though I’m sure the result would be the same.
Interestingly, with many (perhaps all) pistols, if you put you finger in the barrel and press hard, the gun won’t even fire.
(don’t try this at home, or anywhere else).
Cite please.
I’m thinking he means if you put a finger in the barrel and don’t do anything with the trigger, the pistol won’t fire. That’s not what the OP asked, though.
I can’t provide a cite, but it is true. This only works for semi-auto pistols, not revolvers. When you push on the end of the slide it pushes the slide to the rear slightly with very little pressure. when the slide is in this slightly back position the M9 Beretta at least will not fire.
Correct.
It’s a “drop safety” - all of my pistols do this. If the gun is cocked and then dropped barrel-end down, the slide will move back into the safety position, preventing an accidental discharge, even if the hammer falls.
Ah ha. I am familiar with the drop safety on semi-autos. Definitely won’t work with a revolver, though. :eek:
Isn’t the real danger that the gun falls barrel-end up?
Yes, but that’s harder to protect against.
Actually, the way this works might even protect against a barrel-up drop - the inertia of the slide might slide it back enough to engage the safety. I wouldn’t want to test it, though.
Only on most pistols with a moving barrel. and not all that much pressure needs to be applied.
Then there is a danger of death from infection, or even depression from doing such a stupid thing. (Depression as in an act of self destruction).
The drop safety is a block back by the firing pin that is design only to be disengaged by pulling the trigger. I don’t know of any pistol, new or old, that will fire when the slide is pushed out of battery. Even if the trigger is pulled, even if it doesn’t have a drop safety.
Also my CZ-85B, however, I tried it on my Bersa Thunder .380+ and it doesn’t work. So, I would not count on it to work on semi-autos using a fixed-barrel, or simple blow-back, design. So don’t stick your finger in the barrel of anything below 9mm. 
Note: I did not stick my finger in the barrel of my CZ or my Bersa. I checked that they weren’t loaded, and then I pressed their barrels against the wall.
On edit; I see that Gbro mentioned that while I was typing.
Simply pushing the barrel isn’t always enough. It’s the slide that has to be pushed back, even just slightly, that will put the weapon out of battery and prevent it from firing.
You could test it with a snap cap.
Ah, but you’re forgetting the big payout after you sue the gun manufacturer for not plastering dire warnings against firing the gun with your digit down the barrel.