I've killed three of them now, in Lac Ste. Anne County over the past three years. We tried to spot and stalk them in the winter, and it was a difficult stint, as they aren't territorial, so once you spook them, they may run for miles before they relocate.
Two were killed with my 7mm rem mag shooting 140's; one shot in the head (which would have been dead if i had a 22mag!), and one in the quartering towards chest area. both hit the deck immediately.
however, upon taking them apart, i observed some things that made me bring a heavier bullet to the field thereafter. they do have a mass of thick gristle around their rib cages and their ribcages are disproportionately small relative to the depth of their bodies. what that means is it is not easy to get at their vitals unless you have a ton of penetration. Also, a wide wound channel would mean blood track easier to follow throughout the year, as i live here and can hunt them every day of the week, all year round, for a $50 bounty, no less!
anyhow, the weapon of choice for pigs and also black bear was the 338-270HGT with 225gr partitions. My third boar fell to one of those at about 20 yards. it tore through that thing like a softball fired out of a cannon. Through the spine, shattering the shoulder blade, and burying itself in the lower jaw. with 6inches of wound from the top of the shoulder to the spine, the engine compartment was never breached. That pig died of loss of blood, but his heart and lungs were fine. watch for that if you bother to field dress a hog - the relative size of their ribcage vs. their mighty 'hump'. they're totally different from a deer and even more 'hump' than a moose. interesting..
JS