I find that the ones between 60 and 100 pounds are best, but depending on what they eat the bigger ones can be fine table fare also. The shoats split in half and put on the pit are great tasting and tender. They’re better caught than shot, too much meat wasted. Google Cochon di Lait (Suckling Pig) you’ll probably find more info on cooking the young ones.
Try soaking it in vinegar. That gets rid on the wild taste among other things. Cut it into chops steaks etc. Soak overnight, it does wonders. If you think it may be tough cook it in a pressure cooker. It may not be be barbecue, but very edible and the meat will fall off the bone. A shot of barbecue sauce over it doesn’t hurt a bit. Of course you can pressure cook it a bit to tenderize it then throw it on the grill and brown it. If it tastes good and the texture is OK, whose to know.
You can also Jaccard the meat. This is nothing more that a device that pokes small blades thru the chop, steak or whatever to tenderize it. Google Jaccard you'll see how it works.
Sows with little ones are usually pulled down from the nursing and don’t make the best eating. Big boars just smell bad, some eat OK while others should be dumped. Over 200 pounds and they become coyote food here. However I eaten some rather large hogs cooked in a jambalaya, gumbo or some sort of stew that were tasty. Big ones need a cook that knows what he’s doing. Fortunately I have one about a mile down the road so he gets all my big hogs. No cleaning or butchering, just eating for me.
Again a lot depends on what they’ve been eating. Down here it’s mostly sugar cane and corn, but if they’re piney woods rooters eating pine trees and cypress knees the taste or texture can be from bad to awful.
Almost any size can be turned into sausage with the addition of fat back and good seasonings.
Those who beat their guns into plows, will plow for those who don't.-Thomas Jefferson