Some of the most powerful weapons you can create are ones you can use with your bare hands. Think clubs, spears, etc. Check out the ones listed below:

Knives

Carrying a solid knife presents obvious advantages; blades don’t need reloading.
Aside from cutting rope and opening boxes, a knife may save your life someday. A word of caution though:, use it wisely and remember that knife fighting exists only in B-rated movies. In a real life survival situation, a knife must be use stealthily, quickly and decisively.
Meele Weapons 

Weapons like spears, swords, clubs, hammers, police batons, baseball batshell, even a fire extinguisher, a crowbar or a shovel will do the trick in close combat when absolutely necessary. They aren’t as portable as a knife but they’re still pretty good for home-defense in a pinch.

Bows and Arrows

The good thing about bows and arrows is that they can be improvised from scratch, even if you don’t own or can’t afford a high-tech modern bow bought from Sporting Goods. You can easily manufacture one and the same goes for the arrows. The hard part is to train yourself in the fine art of archery, but it can be done.
The biggest advantages when using bows and arrows are that they’re stealthy, silent, deadly and, perhaps most importantly, you can re-use the arrows(unlike bullets) and also you can build new ones from scratch.

The Slinghot

Getting ammo for a slingshot presents no significant problem, and if your aim is good, a slingshot can be as deadly as a firearm from close distance. If you aim for the head; remember the story of David and Goliath. You can use anything from rocks to scraps of metal for ammo and you can even hunt small game if you have the skill.

These were great suggestions from the team at Survivopedia!

http://www.survivopedia.com/diy-items-to-use-as-weapons/#