Quote: "so go figure." Methinks you most likely just punched "the plumbing" and it took 'em a while to realize they were dead. Whereas ya buddy with the .22 probably was lucky (or good) and clipped "the electrical" (just behind/below ear?).
That's a major problem I have with the hyped-up ammo. When it blows up on impact, it just ain't got any horsepower left to reliably get to "the electrical". And on a critter as tough as pigs, may not even get to the "plumbing".