So you're saying you've never seen wounding extend outside of the bullets path, in other words the diameter of tissue damaged is always equal to the projectile's diameter?
Yes, for handgun gunshot wounds that has pretty much been my experience. When I said "significant" wounds, I meant wounds that likely would have had an effect on immediate or early lethality or incapacitation. Handgun velocity projectiles passing in near proximity to blood vessels or solid organs do not tend to disrupt those blood vessels or fracture the capsules of those organs the way high velocity rifle projectiles sometimes do. An exception to the rule sometimes occurred when a projectile struck bone resulting in bone splinters or fragments that caused secondary injury.
It may be that handgun projectiles sometimes cause some tissue bleeding immediately adjacent to the bullet path but not anything that would be likely to result in increased lethality or quicker physiological incapacitation. It may be that a high kinetic energy projectile causes more pain due to the cavitation effect, but pain is near impossible to quantitate and that would be an impossible experiment to do.
Human tissue does not behave like ballistic gelatin. Not only does it contain bone, it is not homogeneous. The closest thing to ballistic gelatin would be muscle tissue. But muscle and other human tissues contain elastin and collagen fibers that hold the structure together. Ballistic gelatin does not. Based on my experience, those sometimes impressive secondary wound cavities seen in ballistic gelatin do not have any counterpart in human tissues when it comes to handgun wounds.
When I was still a lowly medical student at Cook County Hospital the Chicago police were still carrying revolvers and most of them were loaded with .357 Magnum. Pretty much all the police shootings in the city came to CCH so we saw a fair number of .357 Magnum wounds. I don't think many would argue that .357 Magnum carries a pretty high kinetic energy when it comes to handgun wounds.
Back then was just a year or two after the end of the Vietnam war and high velocity military rifles, M-16s and AK 47s, were making their way into the hands of the criminal element in increasing numbers. So I saw a fair number of those as well. I did see remote wounding with those high velocity rifle wounds such as a fractured spleen or liver capsule or even ruptured bowel loops remote to the projectile's path. But I also saw 5.56 mm rifle wounds that had just drilled a nice, neat path through soft tissue with no significant adjacent injury as well.
Based on information passed on sometimes third hand from Vietnam trauma surgeons, the inclination back then was to routinely do extensive soft tissue debridement and make huge laparotomy and thoracotomy incisions to explore penetrating abdominal and thoracic wounds from high velocity rifles, searching for remote organ trauma. As time went on, surgeons became rather more conservative when they found that remote trauma from cavitation was not invariably seen, and in fact, often was not present.
Here is a brief extract from a peer-reviewed medical journal discussing that issue:
http://www.ncbi.nlm.nih.gov/pubmed/15017186