12ga slugs have been rightly known as good stoppers on dangerous game, but tend to over-penetrate in hominids. OATH Ammunition has two new designs that solve over-penetration along with greatly improving reliability in box-fed shotguns.
Above is their 1.25oz 1600fps all-copper slug designed to expand to an incredible 2.5″ and penetrate just enough to punch through a hostile human with little energy left to harm anyone downrange. If you've ever heard the expression: "a hole big enough to toss a cat through," consider that cats can fit any opening larger than their heads, and smaller breeds have heads under 2.5″ in circumference. The copper or aluminum expander die visible in the middle ensures reliable opening even through heavy clothing. The die itself penetrates deeper than the expanded slug.
Full Article: OATH Expanding and Fragmenting Slugs - AllOutdoor.com