So what is the minimum for a humane kill on a hog? Where are you planning on shooting the hog? From how far?
A rule of thumb to realize is that with hogs, if you do not do significant damage to the central nervous system, either by direct or indirect trauma, the hog will run. Even with a good shot to the lungs or heart, so the matter is then one of how far it will run and can you find it? It is not a surprise to see a hog shot and part of a lung hanging out of the exit wound and the hog go 100-150 yards. I shot a hog where the shot destroyed the heart and it still went over 70 yards. I have seen hogs with a pierced heart that went well over 100 yards.
So how much time is acceptable for a hog (or any animal) to survive with a mortal wound for the wound to be considered humane? What is even worse is that sometimes they are shot, maybe even mortally, but because of adrenaline dumps, you can shoot them repeatedly and they don't go down unless you hit them in the CNS or the eventually die from blood loss. I have hunted with folks that would be hard pressed to make a humane kill with a 12 ga. rifled slug gun at 30 yards.
True story - I was talking to a buddy about a hog I shot and lost. He went into his recitation of Capstick and how you need to "bring enough gun." Two weeks later, he had missed a trophy buck at 75 yards with his 12 ga slug gun and had struck the feeder leg in the process. So I had to ask, "How much is enough gun for a miss?"
There is a guy on YouTube that head shoots hogs at 40-50 yards with .22 lr subsonic and does a great job with it. It doesn't take much to make a kill if you can place the bullet precisely where you want it to go and that spot is a critical spot.
Lots of people use .223. I have in the past and will probably do it again at various points in the future. I find nothing wrong with it as a hog sniping round. By that I mean, just like with the guy and the .22 sub sonic, it works very well for single shot kills, when the bullet goes where it needs to go.
Where lighter and smaller calibers have trouble is with less precise shots that do not hit immediately vital structures or do not hit them well. In doing less damage, the hog is less likely to collapse, so it is more likely to run farther, be lost to the hunter, and potentially survive.
Watch Zen Archery's excellent videos, using the Grendel and the Creedmoor.
I watch his videos. In fact, I used to hunt with him. Good guy, fine hunter, but I don't recall him ever using a Grendel, although he hunts with a bunch of calibers. Maybe I missed it, but the only Grendel's I recall in any of his vids are my Grendels, LOL. I have killed several hundred hogs with the Grendel. It and the 6.8 are very comparable for typical hunting distances.
6.5 Grendel and 6.8 SPC are not the be all to end all of hog calibers, although both are quite good, particularly with good bullets such as Hornady SST or Berger VLD-Hunting. Both are far superior to .223/5.56 and are both still quite manageable for followup shots as needed, more so than with some larger calibers favored by many hunters, such as .308, .243, or even 6.5 Creedmore.
I went to the Grendel from the .308 after a surgery and by the time I had healed up enough to go back to .308 had discovered that I was not being less successful with the Grendel on hogs than with the .308. Between that, less recoil, and increased capacity, I stayed with the Grendel.
I like to try out different hunting bullets in the 6.5 Grendel. Some work much better than others. The nice thing about SST or VLD-Hunting is that both tend to do damage beyond the immediate wound channel, thereby increasing your odds of a successful, quicker kill. Both penetrate well, also. Neither is particularly meat friendly, however.
If you want to use a .223 and can make a steady shot and hit within a 2" circle at whatever distance it is that you are shooting, know your hog anatomy and where your shot is going to go relative to the orientation of the hog, then .223 can be fine. If you are not making CNS shots and hunting where thick brush is nearby, don't be surprised if you lose a bunch of hogs.
