I did a test this morning on a small coyote at about 50 yards using MK262 Mod1 bullets out of 20" AR with a Swar Z6i 1-6 brt scope. Sorry about the pic it was still early.
Nice! I shot one in the neck last week with elcheapo Remington CoreLokt 55gr soft points at about 70 yards, right in the neck like you, and the results were far less impressive on the exit side but the yote was DRT. Keep testing!