Tanks
What's inside those mechanized fighting vehicles?
Firearms
See the insides of rifles, handguns, automatic weapons, etc.

Illustration by Ray Quigley shows an anti-sub device from 1950 termed “the hedgehog.”

It lobbed multiple depth charges all at once at the presumed submarine location.  Charges were slightly angled so that they would land in a spreadout, scattershot pattern, covering a wider range.

 Click to Enlarge to 695 x 768 px:

Ship-Based Anti Submarine Defense Cutaway, 1950

Ship-Based Anti Submarine Defense Cutaway, 1950

Source:  Popular Science March 1950