I posted a thread awhile back on .38/.357 cal. small game points. Below are what they looked like. I had a hard time keeping the blades in even using JB Weld.
I have since come up with this design. After testing I have found it to be a much more durable design. It works much like the ACE Hexheads.
To make this style you use the same materials:
* .38 or .357 cal. cartridge
* a square of banding strap
* pop rivet
Drill a hole in the expended primer of the cartridge (don't try this with a live primer )
Drill a hole in the center of the square of banding steel
Pop rivet it in.
Bend the corners up to a 90 degree angle.
You're done!
This is the one I actually shot and the corners didn't lose shape.