I personaly witnessed a shot (I was ten tree' s away) my buddy took on a ~250# boar with a sidewinder. (The scale was missing in camp, but both of us couldn' t lift him onto his 700 polaris, we had to use my quad to drag the hog onto his rear rack.)
He shot it about where you' d shoot a deer, and got a pass through with the arrow falling out the other hole about 15 yards down the trail the pig left on. He shot it a little behind where most of the sheild was. The sidewinder opened just on the other side of the fat layer, but before the ribs. This pig still went ~ 80 yards before pileing (SP?) up.
He shot another larger pig with this same broadhead without getting a pass through. He said it only went 30 yards before expiring. Upon gutting the boar he said the lung area was nothing but jelly.

He was using an older (but great) Mathews 3d-pro with ~80# pull shooting some overdraw cut down aluminums at @ 270 fps. Not sure what his K/E was, but it was up there.

I personally lost two out of three pigs last year using a 1" cut 4 balde fixed broadhead. I feel it was the smaller cut that cost me as both the pigs I lost had what looked like perfect pass throughs. Plenty of blood for ~80-150 yards, and then nothing.
The one I did harvest only went about ~50-60# and was shot at a severe angle. DOA

Me personally, I plan on shooting my next pig with a large mechanical. If it' s a bigger pig I will wait on a quartering away shot. In my opinion, the more damage done will equal the less distance traveled after being hit.