The little .223/5.56 with heavy for caliber bullets is a perfectly suitable round for hogs with the proper shot placement at reasonable ranges. For a number of years working for a state agency, part of my job was feral hog removal and I did so with several different calibers, but my pet rifle was a .223 Remmy 700. The two bullets that worked for me quite well, although very different in construction, were the 75 gr. A-max and the 75 gr. Scirocco sitting atop of 25.3 gr. of Varget at around 2830+/- fps. Out to 200 yards this was bad medicine for hogs. . .deer too. Documentation of the hogs shot had to be recorded for the biologists and the largest hog I killed during that time was a male hog of 378 pounds. The shot was at 104 big steps on a mowed power line easement with the A-max. I held low and tight for the crease behind the shoulder. At the crack of the shot he hunched-up as on his tip toes and took several steps backwards in a half circle with his mouth wide open as to scream, then tipped over kicking. Total distance traveled maybe 15 ft., but very slowly. There was no blood on the scene and just a small leaching spot where he was hit on the hide, I think that the cartilage from the shields closed up the small hole. When I opened him up, the organs in the chest cavity looked like a five gallon pale of Smuckers grape jam. This same scenario played out on many hogs (100's actually) with both bullets. I did get more pass through shots up close using the Scirocco's, but the end result was always the same. Shots placed where the head and neck meet was an instant lights-out by far. "My theory" for this working so well was the fact more times than not the animal absorbed all the bullets energy and shrapnel exploded in the chest cavity turning it into a food processor. The larger calibers I used (308 Win., 6.5 Swede, 7mm RM – each w/140 to 180 gr. bullets) had more animals leave the scene when shoulder shot, only to find them dead a distance away. . .but dead non the less. I think that the heavier weight bullets traveling at high velocities don't expand as much and pass right through, therefore they do not transfer the energy to the animal as well. This is at short range of course (under 150 yds.), at longer ranges it is a different story. In the hammocks and tight quarters I always wanted to try a .44 mag rifle of some sort to see how that would perform. . .under 100 yds. I think that would be bad news for any hog! Just my $.02 on the matter. Good luck.