Except for licensed firearm dealers, it is unlawful for anyone to buy or sell firearms or ammunition. The same goes for firearm manufacturing, only the Inspector–General of police can grant a license to make and repair firearms in Nigeria. However, such persons must be duly documented and registered.

https://lawpavilion.com/blog/an-overview-of-the-gun-regulations-in-nigeria-the-current-stance-and-the-way-forward/#:~:text=Except for licensed firearm dealers,be duly documented and registered.