[jyl]

There are special loads designed to fragment and not over penetrate. E.g. the venerable Glaser Safety Slug. https://www.shootingillustrated.com/content/is-the-glaser-safety-slug-good-for-self-defense/ I suspect they may have real drawbacks but some benefits too. There may be better designs out there. I’ve no personal experience with them. I load my defense guns with old fashioned hollow points.