This book is basically an illustrated argument against the concept of gun-banning legislature being effective in keeping firearms out of the hands of criminals. There are many photos and examples of improvised single shot weapons using the .22 catridge that hardly look like conventional weapons. What they lack in stopping power and accuracy, they make up for with relative ease of construction, accessability of materials, and concealment. Many of these examples were confiscated from inmates in prisons. Which raises the question: if criminals can make guns in federal prisons, then how can gun laws prevent them from doing so when they are free in the streets?
Later in the book, there are examples of more sophisticated weapons, like reproduced AK-47's and the like by local craftsmen in third world areas.
It's interesting (and to some, perhaps unnerving) to see a shotgun made by a 15 year old from simple pipes that is capable of firing a 12 gauge round.
What could have made it better is if it featured cutaway illisrations showing the inside of some of these devices, like where the round is places, where the firing pin is located, and the mechanism that activates it.
Overall, if you are interested in improvised weapons and/or odd devices, then its worth the money. Just be advised that it is not a how-to manual.