Isekai Sniper wa Onna Senshi no Mofumofu Aigan Doubutsu - Vol. 6 Ch. 30 - The Princess's Transformation (Part 10)

[CountryMage]

It has already been shown in the series that the MC obtains these weapons from our world. So this weapon was operational, and it was brought to the MC’s world by the god.

A lot of these weapons were already there, but completely unusable by other people, the MC digs up rusty lumps of garbage, and like Conan, just knocks the rust and age off powerful weapons.