As I've mentioned before, I am very frugile. That is a progressive word for cheap..!!!
They make a rubbery foam material and one use, is archery targets. It too is self-healing. I cut cubes out of this material, paint it blaze orange and shoot that. I may glue squares together to get larger cubes. The bullet will pass right through it so it doesn't go flying. It's cheap and lasts a long time.
Be Safe !!!