When I was in the 6th grade we read a book which was a collection of smaller books (or stories), which was perhaps a text book compilation. This book included The Jungle Book, but also had a few stories that I don't recall the name of.
In one of the stores a man travels to an alien planet with a disintegration gun, there he field tests the weapon on some hostile monkey-like creatures. Things go poorly, he gets injured, he shoots part of his ship with the weapon, leaving him stranded on the alien planet. At the end the people who hired him come looking for him and find him living on the land with a bow and arrow, and using the gun as a hammer.
Since the story continuously called the disintegration gun "the weapon" I expected it to be called that, but I couldn't find anything similar online.