Empty magazine

Magazines are ammunition storage and feeding devices for various firearms. After the ammunition is spent, the soldier usually disposes of it, although using it to divert enemy attention by throwing it and causing it to make a noise isn't unheard of.

Usage
Naked Snake, during his mission in Tselinoyarsk, can use up all his ammo to get magazines. He also could use it as a method of distracting enemies.

Big Boss's Militaires Sans Frontieres, due to being a mercenary organization, often used weapons in battle, and often uses up magazine clips, which also acted as a method of diverting the enemy. In addition, the Militaires Sans Frontieres' R&D Team could also create empty magazines specifically for the purpose of diversions.

Raiden, during the Big Shell Incident, used any spent ammunition clips as a diversion.

Solid Snake, during Liquid Ocelot's insurrection, utilized this as a primary method of distracting enemies after spending ammo.

Behind the scenes
Although empty magazines did not appear in Metal Gear Solid, they did appear in its remake, Metal Gear Solid: The Twin Snakes.

In-game weapons description
"An empty ammo magazine. It is useless as a weapon, but it can be thrown to make a noise and thereby distract the enemy. Added to your inventory each time you reload a gun."

- Empty Magazine weapons description from Metal Gear Solid: Peace Walker