Hello Japan!
About this "gun":
Two pipes of some kind were
installed on a wooden board
using glue tape.
(Tape used by electricians.)
Propellant is known to us
"Round eyes" as black gowder.
There are three components used
For the production of black powder.
These same three components
also used as a firecracker explosive
(However, the ratio of materials is
different).
This was an improvisational weapon.
Made uniquely.
He may have used only one Big
Ball Bearing as a projectile
in each barrel.
Or this gun may just have provided
needed flash and bang
for targeted readers.
Deadly projectile
flew from
more sophisticated "silenced"
gun.
***
Ignore ridiculous Americans
Reporter who identified it
"Shotgun".
All their knowledge
is only of the
"double-barreled shotgun"
that can be seen in the movies.
Not from other twin barrel guns,
for example, African Safari Rifle!
(Because the reporter does not eat
natto, nori, and miso soup for
breakfast,
brain function is very poor. ).
A toast from Minnesota!
***
"Google Translate".
Many iterations.