You know, I haven't used an extensive number of calibers. I started with a .45/70 that was outstanding. With .325 gr Leverevolution ammo from Hornady, drop was minimal out to 200 yards which was well inside my normal shooting distance. The only problem was that it would not work with typical night vision due to recoil. It did work with digital night vision (Pulsar Digisight), but the recoil beat the hell out of the rechargeable batteries. I was using the Gen II+ NV behind a red dot sight on my .223/5.56, but the red dot was too limiting on my range shooting. So I went to a .308 with the Digisight and the batteries survived longer and the optic did well. I probably would have stayed with the .308 except for a medical issue. In 2015, I was hospitalized and needed abdominal surgery and the doctor told me that .308 wasn't something I could withstand for a while, but I wanted more than .223 and ended up with 6.5 Grendel. I have used 6.5 Grendel for a few years now and think it does very well. I have also been testing a lot of different bullets with it, and some don't do very well at all, some do okay, and some are absolutely great. It doesn't beat up my optics, is good for video, and just seems to generally do well with hogs. Of course, there are a lot of calibers that will work just fine for hogs. Grendel isn't special in that regard.
I have hunted with a lot of people who use a variety of different calibers, mostly in AR platforms, but not exclusively. I have no wish to inspire any sort of caliber wars. I know of folks who hunt hogs with .22 lr and who are successful with it because they are very selective with their shooting. I have watched guys with .338 Lapua and .458 Socom have trouble dropping hogs because they were such poor shooters under the circumstances, despite the ranges typically being less than 150 yards. I have seen guys who make good caliber choices, but poor bullet choices have trouble downing hogs.
With that said, the two calibers I have seen that seem to give the guys the most frustration are .223 and .300 Blackout. Both can be used for hog hunting just fine, but they are calibers where people really need to understand the limitations of what they are using. Particularly with .223, I feel shots need to be just that more more precise. Most people don't like to admit it, but the more destructive the caliber, the more leeway you have with less precise shots. The same can be said for different bullet types within a given caliber.
We all want to think that we are all great shooters and that we can make great kills at hundreds of yards with a BB gun, but the reality of the matter is that often in the field, things like buck fever, physical exertion, general tiredness (sometimes we hunt all night), improperly assessed distances, movement of the animals, wind, visibility, etc. can all lead to shots not being the laser accurate instant death bullets that we want. As such, larger and more powerful calibers tend to do better than smaller and less powerful calibers. Properly expanding/fragment ammo does better than ammo that doesn't properly expand or fragment. A bullet that pencils through both lungs with a nice stable flight will undoubtedly kill the animal just as dead as a bullet that expands and cuts a jagged 1" diameter ragged permanent wound cavity through both lungs, but the former hog may run several hundred yards and live a lot longer than the latter hog that will likely be down within 100 yards. The moral of the story here is that the larger the wound cavity in overall volume, the more likely the bullet is to hit vital structures and to do more significant damage to vital structures.
Based on my own observations, pick a good centerfire caliber and then pick good bullets that will properly expand or fragment at the distances you typically will be shooting. That means figuring out how the ammo performs at a given velocity. A change of a few hundred feet per second can have a significant impact on how well a bullet expands or comes apart. You also want a round that penetrates well so that it can reach the necessary structures inside, maybe after already hitting heavy bone. I like Hornady SST 123 gr. factory ammo which leaves my gun at over 2500 fps and Federal Speer TNT 90 gr. factory ammo that leaves my gun at ~2800 fps. These both expand and fragment, creating relatively large wound cavities and their fragments tend to damage a lot of the surrounding tissue. The downside, of course, is that a lot of excess meat is ruined, which matters to meat hunters. Otherwise, I found that bullets like handloaded Speer Gold Dot 120 gain (2540 fps) opens beautifully and cuts nice wound channels through the hogs and doesn't pollute a lot of meat with excess bits of lead and copper jacket. The 129 gr. Hornady SST (loaded by Alexander Arms) had a muzzle velocity closer to 2300 fps (IIRC) and didn't fragment like it lighter version, but tended to expand more like a softpoint and not pollute a lot of the surrounding meat, but still penetrate well. -- bullet choice and velocity relative to bullet performance are important considerations.
So hunt with what you like in terms of caliber and be able to shoot it well. Pick good ammunition for the caliber and the distances you will be shooting. Hogs are pretty resilient creatures if if you don't make a CNS shot (spinal cord, brain stem, brain), the hog is going to run. How far it runs will largely be determined by where you hit the hog, the trajectory through the hog, and how much damage your bullet did going through the hog.
