While not having experience with this cartridge on deer, I would mention That I did have experience on groundhogs in soybean fields in the Midwest, way back when, and other experience as well. Found it adequate for clean groundhog kills out to 250 yds. After that
many got back to the hole. We assume they did expire in the comfort of family and friends, but who knows for sure. From some of the performance reports of the 223 in other threads, I thought, well maybe I'm just missing something. So I would be very curious as to what other opinions are.