improvised firearms

like a gun it is a weapon that fires a bullet with explosive pressure out of a barrel, typically using a trigger system.
the differences from a regular firearm is how it is made, and what it is made from.
like snowflakes they are always different, with different metals and inconsistent design.
they usually are single shot reloadables, have simple designs, and are unsafe.
sometimes they are inspired and built from parts of other weapons like the ak-47.

police officer 1: we found a stockpile of improvised firearms during a raid?
officer 2: are they functional?
officer 1: no they are not.