Sorry for the impending wall of text, but I do a bit of game design myself and I feel a little strongly on this topic in the context of game mechanics and finding a suitable degree of representation and abstraction, since it’s quite applicable to my own game. Not all of this is applicable to CDDA specifically, but I enjoy thinking about and discussing it as discourse.
I know that yes a bullet is literally “crushing” the tissue to form a cavity, but the wound it causes is very different from any form of wound that could be caused by a hammer or similar blunt object, and - in any sort of game design with in-depth damage mechanics - you’ll almost never find it represented as a “bashing” attack.
For game mechanics, I always interpret it in terms of the sorts of wounds weapons and projectiles cause in soft tissue specifically. A cut (such as a laceration or incision) is very different to a contusion (caused by blunt force trauma) which is again very different to a puncture wound (being stabbed or impaled) which is again very different to a gunshot wound. The four types of soft tissue wounds I’ve listed here would cover all the basic forms of damage in game with different forms of protection being better at protecting from some of these than others. I find that these four basic types provide the best mix of abstraction and accurate gameplay mechanical flexibility.
On the topic of “pierce” being exclusive to firearms, I’m just using that word as a label to generically ascribe the type of wounds you see in gunshots - it would also extend to other small, high velocity objects that might literally be crushing tissue to cause wounds (e.g. high velocity fragments from explosions and potentially exotic attacks from creatures) but behaves very differently to blunt force trauma which is what bashing damage is meant to represent. Honestly, I picked that label since it’s used in GURPS which is a very good system for universally representing the different types of wounds someone could suffer. A stiletto striking the body (and intervening material) produces effects comparable to a spear or arrow strike, and not comparable at all to a gunshot wound. To portray what you’ve mentioned in gameplay terms, if a melee weapon could be given an AP value, the stiletto would have a higher one than a spear, but would ultimately be causing a smaller and cleaner wound than a spear.
Classically, yes, there’s the three types of physical damage and armour you see in a lot of games, but this model isn’t as applicable when you begin to incorporate firearms into the picture. The whole idea that sparked this part of the thread is from @TheZoneWizard’s comment that kevlar isn’t like chainmail or a steel plate (as quoted it “isn’t cut resistant”), hence the need for at least one more basic damage type to represent this.
Indeed, collectively the types of damage caused by an explosion are called blast injuries. In academia and medicine, you’ll often find them breaking it down into specific wounds which usually include fragmentation wounds (which you’ve already covered), flash burns, and blunt trauma from the overpressure. But this is quite unique and differs from other blunt trauma in that it does extensive damage to internal organs and causes amputations and other such injuries that we don’t associate with typical blunt trauma. I think damage from just overpressure could be, for gameplay purposes, adequately and simply represented with large amounts of bashing damage tbh, particularly to the torso. You could also add another damage type specific to overpressure - there are already many special types of damage in the game such as poison, fire, cold, radiation etc - but sometimes it’s sufficient to use the more basic mechanics than develop new special rules. And with that statement, I’m led to my next part of the post…
Absolutely, to bring it all back around to CDDA, while playing I don’t really think of these things and I still enjoy the game with its current level of abstraction. I haven’t actually looked at the projects open on github for a long while, but with the way the game has been going, I don’t have any doubt that Kevin et al would ultimately want to expand on the wounding system and have specific treatments using up different resources for different types of wounds (so players stop applying disinfectant to a perfectly sterile bruise). I’m hopeful that the basic damage system will be refreshed in the process too. In the meantime I’m happy enough fooling around in the cataclysm as is.
PS: don’t want to be too pedantic with this, but the tungsten and steel penetrators aren’t meant to provide “weight”, they provide strength and rigidity to the projectile so it won’t deform or destabilize as much as a simple copper-jacketed lead projectile.