Citation? If such a round exists I'd be very interested to see it.
Of all the 5.56 vs drywall tests I've seen (and there are lots out there), they never make a hole in drywall larger than 5.56 unless it has yawed, and even then it is a keyhole no larger than the un-deformed round. To make "a huge hole" in drywall it would have to expand massively and immediately, and I've never seen a 5.56 round capable of expansion when hitting drywall. Even frangible rounds essentially turn into 3 or 4 projectiles after passing through drywall, but I'd never say 1/3 of 55 grains at 2000+ fps would "not significantly harm a person".
Of all the 5.56 vs drywall tests I've seen (and there are lots out there), they never make a hole in drywall larger than 5.56 unless it has yawed, and even then it is a keyhole no larger than the un-deformed round. To make "a huge hole" in drywall it would have to expand massively and immediately, and I've never seen a 5.56 round capable of expansion when hitting drywall. Even frangible rounds essentially turn into 3 or 4 projectiles after passing through drywall, but I'd never say 1/3 of 55 grains at 2000+ fps would "not significantly harm a person".