You want the Trope Finder for this sort of question.
Perusing Guns and Gunplay Tropes yields Finger in a Barrel.
Ah yes, I remember that one.
However, that doesn't seem to cover all possibilities, namely with other objects blocking the barrel.
For example, there are instances where a barrel is split by another bullet, or another object is crammed into the barrel, causing the firearm to malfunction catastrophically.
The description does say it covers objects besides fingers, as do the examples. Tropes Are Flexible and the description is more important than the name, but this particular name does seem limiting.
The Unknown
Corking The Gun Barrel or Clogging The Gun do sound like better names than Finger in a Barrel.
If a tree falls in the forest and nobody remembers it, who else will you have ice cream with?
So, this brings me around to the point that I am getting to:
Should we rename the trope to something like "Corked Barrel" or "Corked Gun", which encompasses far more objects than appendages, in both the name and trope description?
The Unknown
You'd need to go to the Trope Repair Shop. That's where most name changes take place.
If a tree falls in the forest and nobody remembers it, who else will you have ice cream with?
Just wondering, do we have a trope where a gun is plugged by an object, which results in a spectacular failure?