[HT] Hypothetical Multi-Purpose Shotgun Slug

[Michele]

I might be wrong, but I suspect that these rounds do already exist in reality and are not even experimental any more. And yes, you can stat them in GURPS, with GURPS High Tech, p. 103. The box on that page provides examples of APHC slugs for shotguns. They get an armor divisor of (2). Also compare with p. 167.