KirkEDGE,
Did you field-dress the pig yourself?
I ask this because an awful lot of people, seeing a small exit hole, assume the bullet did not expand. But that normally isn't the case, and the way to find out is to examine the organs inside the chest cavity. If they have a big hole in them, then yes, the bullet did expand.
The small exit hole is common with a lot of bullets, and they don't even have to turn into wadcutters, as BobNH has pointed out they sometimes do. Nosler Partitions, for example, tend to leave an exit hole just a little larger than the bullet's original diameter, yet normally tear a good-sized hole in the lungs, especially the lung nearest the entrance hole. This is because a Partition opens up violently (the front end is very soft lead) and then the frontal jacket often folds back along the shank of the bullet.
AccuBonds work similarly. Often they end up expanded a little wider than a Partition, but at close range the frontal jacket folds back along the shank, or even breaks off.
