One of the deer I've shot with 223, 69gr SMK in wisconsin. I wanted to take my favorite AR which I shot and reloaded for enough I figured I could send the 69gr through a deers ear but I was invited to the area and I didnt want to take risky shots so i said I would wait for a double lung shot.
I was filling a doe tag late in the WS season and watched and a doe slowly walk up broadside. Through and through double lung shot only left a few drops of blood through a wisconsin field FULL of deer tracks, she went nearly 300 yards and I finally found her in the neighbor's swamp well after dark. If I remember correct the only blood I saw was a few drops in the first 40 or 50 yards then nothing until I saw blood smeared on grass 10 yards from where she lay.
The bleeding was bizarre, on the exit side under the skin was full of blood. The bullet exited over 6 inches away from the off shoulder, I wanted to save the heart for dinner, but the whole leg was swollen, bruised and full of blood. I saved the shanks for Aso bucko and the rest of the leg I had to throw out.
That single 69smk perfectly placed ruined more meat than any of my 30-06 deer.....? It was like the wounds sealed up right away but all the bleeding got forced under the skin and down the frantically running leg and into the meat for some reason. There isnt much meat on the front legs to begin with and I tried digging around to save some but the whole leg was seriously bruised with fresh blood everywhere. Most of the rib cage on the far side was completely saturated in blood also, the lungs were destroyed but she ran a ways and somehow the lack of exit wound forced blood into the meat.
This must be a fluke but over all I would say get a bigger gun, some people know their guns, ammo and skills well enough to make a 223 work no problem. I normally bow hunt but when I rifle hunt I want to hit them hard and 223 has never been known for knockdown force. .223 was too small of caliber to even legally hunt deer with here in MN until a few years ago.
If I was going to hunt with 223 I would bring 65gr sierra game kings, they expand and frag a lot more than 69smk but still penetrate unlike varmint bullets. Maybe the 53 tsx I'm shooting at 3330fps but I think the 65gr might hit harder and drop more energy. Theres other good bullets I havent tried but varmint bullets arent worth anything more than hunting paper and rabbits.
If you shoot a lot and have a good rest culling does with head and neck shots from 223 works great but then there isnt any reason to discuss bullet selection. Heart and liver are my favorite parts, I love field dressing head shot deer. But for the average hunter around here who MIGHT check their scope zero with factory ammo once a year taking head shots in hunting conditions with your heart pounding doesnt work.
P.S. I've seen a deer dropped with 300mag that skimmed off the top of the head straight between the ears. Not even a drop of blood, just missing tiny strip of fur.