This whole conversation has gone on too long and I feel weird getting this involved as a moderator- so I'll try to back out a bit here.
I guess I'll just say this, it really bothers me that I spent several years researching the properties of gunshot wounds, as well as the laws of physics themselves to make absolutely sure that I could speak on this issue without blowing around hot air, only to be told that I'm wrong because people choose to believe stereotypes established by entertainment outlets. They choose to believe what seems right because the idea that the world doesn't work as previously thought just isn't palatable.
I want to clarify that this isn't directed at anyone in this thread, but phrases like hydrostatic shock, ramblings of pressure waves and shockwaves- these were first uttered by someone who-pardon my language- was talking out of their ***. These things are cosmicly hilarious and nonesensical to a physics major.
I wish I could just let you know what is in my mind
because I can't begin to articulate into words how little sense some of this stuff makes, alot of people have been had by a few know-it-alls who think people will just assume they know what they're talking about because they use lots of five-dollar words. This seriously lays heavy on me, because it makes me wonder what other things we could have totally wrong because it just seems right. For all I know I could be horribly wrong about all kinds of things because I didn't delve into research about them.
I just want to make clear that I am not an advocate of the hydrostatic shock theory myself, however I do acknowledge that two identical objects hitting a medium like flesh will produce a different size temporary cavity and damage to surrounding tissue or nearby organs depending on the impact velocity.
Also one thing that has been completely overlooked in this discussion about terminal ballistics is the effect of hitting bone. Bone takes up quite a significant part of the human body, and thus the chances of hitting bone is always going to be high, and this is where rifle & pistol rounds really stand apart.
A rifle round that hits bone will usually result in absolutely horrific injury, whilst the same cannot be said for pistol rounds, and again this is due to great disparity in the velocity of the projectile.
A rifle round that hits bone will either explosively fragment or immediately start tumbling, a deadly prospect with a projectile often going twice the speed of sound.
This really is one of the primary reasons that rifle & assault rifle rounds are so much more deadly than pistol rounds, the potential for lethal injury is quite simply a lot higher with rifle & AR rounds.
The same is seen in warzones around the world today, even when talking of the 7.62x39 M43 round, which is sometimes known to cause needle hole injuries, however in that case the victim has always been lucky enough that the round only struck flesh. Ignored is the fact that there are just as many cases of people being hit by the old AK47's firing surplus M43 rounds and suffering absolutely horrific injury, and this is mostly a result of the projectile striking bone inside the body.
A close friend of mine who had two tours in Afghanistan saw one of his colleagues get killed from a hit by an AK47 to his collar bone. An otherwise non-lethal place to get hit by something like a pistol, but as it turned out not by a rifle round. The round hit the collarbone shattering it and sending fragments down into the upper torso, one of which went straight through his colleagues heart.