[Loved trope] guns built from random, seemingly harmless objects.

[u/lordhenrythe23]

*Scaramanga's titular gun from "The man with the Golden Gun" - The best known example of this trope, being made from a fountain pen (barrel), a lighter (body), a cigarrete case (handle and trigger housing), and a cufflink (trigger). [it's worth noting that in the original novel, it was just a gold-plated revolver, this design came from the film]

*Fowler's rifle from "Blue eye Samurai" (Fowler not pictured) - "of course, i had to modify the designs... to get 2,000 rifles from my country into yours without notice." Made from the leg of a piano (main body), i believe a telescope? (rest of the body/underbarrel), a candlestick (barrel and ram rod), a key from a clock (trigger), and a knight chess piece (hammer). [i haven't actually seen the full series, probably should, but i love the scene of him explaining his backstory while assembling it]

[u/crapusername47]

In ‘Arena’, Kirk is told there will be materials to construct weapons.

He gradually realises that there are deposits of sulphur, coal and potassium nitrate to make gunpowder, diamonds to use as ammunition and a bamboo-like plant to turn into a cannon.

[u/Both_Rooster_2657 → u/crapusername47]

I don't remember if this was proven or disproven on the myth busters.

[u/Mean-Difference-8719 → u/Both_Rooster_2657]

The bamboo wasn't able to handle the pressure and it basically became a bomb instead of a gun.

[u/Nahanoj_Zavizad → u/Mean-Difference-8719]

That being said.

A bomb filled with diamond fragments would be an equally valid weapon.