I have zero doubts that the 32 H&R Mag can serve as a defensive caliber. Toward the end of my career I did the secondary side of a homicide case (crime scene work) of a 'Frequent flyer vs, regular customer' discussion between adverse parties. At least one side of this discussion was conducted with a 32 H&R Mag, and this became known as soon as we moved the body of the discussion's 2nd place finisher--because one (1) each Hornady JHP fell out from within the portly man's shirt after through-and-through penetration of lungs front-to-back (IIRC). Other than land & groove impressions, the utterly unexpanded JHP looked like it could be reloaded and fired again if someone was so minded. This recipient was about 6'5" and 315#, so that bullet did no small amount of media penetrating.
To me the 30s & 32s are all 'Fun guns'--small game numbers and tin can rollers. The 30 Luger & Mauser, the 32 Mag & 327 Federal, and the 7.65 MAS pistol and 30 Super Carry are among us--they can, will, and have repelled boarders capably for 125 years or so. I just don't think light-tackle angling mindsets translate well to the hunting fields or to exchanges of finality.....use enough gun.
That's my story, and I'm stickin' to it.