Get these at the hardware store, they fly straight and work great.
You will need a pack of crown bolts t nuts 1/4 20.
The middle will have to be drilled out some so your field point can thread. Use a 5/16 bit, drill it out til its about 1/8 deep so your point grabs a few threads.
Go have fun testing them out on some critters.

Great idea

Real great idea. Im on my way to the hard ware store now.