A 60 year old man in Japan was recently arrested for building homemade guns of his own design. According to him it was his hobby for the last 40 years. He used scrap anvils as a source of hardened steel and crafted his own ammunition using toy caps and casted lead bullets.
A double barreled muzzle-loading percussion lock. The barrels are rotated between shots.
A submachine gun which is trying to decide whether its an AR or a Thompson.
A compact machine pistol. The neat thing about it is that It appears to accept Type-14 Nambu magazines.
A cartridge firing double barreled pistol:
This revolver probably took the most amount of time and dedication: