Pistol by Makoto Yamaguchi

Diagrams in Fun Origami World by Makoto Yamaguchi
Diagrams in The A to Z of Origami in English by Makoto Yamaguchi
Folded from a square of origami paper

Pistol by Bill Caruba

Diagrams in The Magic of Folding Money by Bill Caruba
Folded from a toy US dollar bill

Sword by Peter Farina

Diagrams in Dollar Bill Origami by John Montroll
Folded from a dollar bill-sized rectangle of Vietnamese wrapping-paper