You could also use a chunk of plastic or metal if that’s all you have to work with. Piece of wood– I used two strips of 3/4″ that were 1/2″ thick and about 15” long and glued them together.A single piece of wood is good too, and saves a step because you don’t have to glue it.This is pretty easy to make, it has about a 25-30 pound draw weight, and can be used for taking small game.
But a small crossbow for hunting small animals would probably be okay.
I wouldn’t give the other guy too good of a weapon though because I wouldn’t want them to be able to turn them on me. This is also a valuable skill that gives you something that you can barter with if you care to do so. Learning a skill like making your own weapons helps to ensure your safety and improves your chances of obtaining food. In the event of SHTF or TEOTWAWKI, any kind of weapon that you can make to use for hunting or self defense will be a huge asset.