The 9mm shotgun was first made in England where it acquired the name "Garden Gun". It actually fires a rim fire "shot shell" available in shot sizes from 6 to 8 shot. As stated it was made for garden pests. They never caught on in the US, but winchester did make on for awhile called the model 36.
I guess I missed where someone said they planned to get one.what in the world would your purpose be in having / or shooting something where the ammo was expensive or hard to come by