Bullet overpenetration?

[dawnFinder]

So I’ve been playing an archer build (14 STR & PER, maxed flaws, no traits) in the latest version, and I’ve played quite a bit of the previous versions, and I’ve only ever used guns to take out things that my arrows can’t penetrate and/or against things I’d really rather not be in extended melee with (wolf/black widow spiders, robots, skellies, etc), meaning the only thing I’d ever need aside from my bow is an assault rifle with a good magazine size or a pistol if I’m low on space.

I’ve found the heavier ones to be generally underwhelming at (zombie) crowd control, partly due to unwillingness to spend 10 ammo per shot for burst fire (and is rather inefficient even if you do, barring lucky positioning), but mostly because I could take five steps back with a longbow to fire a couple more shots to achieve mostly the same effect without rousing the entire town, and wood arrows are easier to come by.

Shotguns in particular have it pretty bad since ammo for them is relatively scarce (in my experience) and more often than not attracts more zombies than they would kill, not to mention reload time reducing overall fire rate and thus the rate that regular zeds get killed, making them only really good for reliably oneshotting brutes that get too close, something that can be done better with an assault rifle or even a high caliber pistol (both with sufficient skill of course), or intentionally drawing huge hordes to clear out.

So I thought, what would help firearms here? We already have underpenetration (shots doing less damage/outright being harmless due to armor) so why not have overpenetration, where a shot is so powerful it punches through the body entirely, into the next one and, if its powerful enough, through THAT one and into the next, etc. The shot would of course do reduced damage after each penetration depending on (current) bullet velocity, caliber, the body it’s passing through and so on. I have no idea how headshots are going to factor into this though, but it would give firearms enough of a boost to be somewhat viable in clearing towns, instead of relying on kiting and spamming arrows all the time, or simply funneling them into a chokepoint and meleeing the horde into submission (as with my other build). Balancing it so firearms don’t become overpowered as a result is another thing though, what do you guys think?

[Misha]

Seems cool.
Using this idea would actually give me a reason to use a weapon aside from the Marlin.
At 4 firearms+rifle, it performs roughly the same as any other higher caliber rifle.
This would make using high caliber rifles actually viable (high caliber pistols don’t really need the buff) because the increased damage of higher calibers is really only an advantage against hulks and pretty much only results in an increase in “aggro” compared to the Marlin.

[KA101]

Yeah, the M249 was pretty good about blow-through back in Survival Crisis Z. High-powered FMJ/AP rounds being able to overpenetrate is probably worth considering here.

[Goober]

I have spent the last few days playing with partial differential equations and now have a set of equations for calculating the amount of energy left in a projectile at any given moment or location. It only models loss of energy due to drag through fluid (air, water, etc…).

Since we dont have to worry about drop due to gravity, we could extend the simulation to model different projectile types impact and passthru. The equations require the following: fluid density, projectile mass, projectile initial velocity, projectile coefficient of drag, projectile cross sectional area.

These are available. A typical 9mm FMJ pistol round: 9grams, 300m/s, Cd=~0.52, A=pi*(0.0045)^2, then air is 1.2kg/mm^3.

Balance F=ma (initial force) with F=1/2(densityAreaCd)v^2 (force due to drag).

Taken further, we can estimate based on projectile material and energy whether the target hit is armored enough to stop the projectile, fragment the projectile, mushroom it, or pass it on through (and how much leftover energy it has).

This can extend to other weapon types. For instance, while researching, I came across data that shows an expert karate strike carries the same energy as the 9mm projectile above. Difference is in impact area (approx 10x the area for the karate strike as the bullet).

[dawnFinder]

It just occurred to me that zombie hulks and brutes are two different zombie types. And that I’ve never actually encountered a single hulk in my time with the game (if you can actually believe that). Necromancers and masters, yes, but no hulks, I would have noticed an unusually fast and strong zombie cop. And I’ve definitely survived long enough for it to be eligible to spawn (24 hours), am I doing something wrong, or is the wiki outdated and it actually spawns much later?

[ted]

Guns don’t need a boost. Their problem is that really dangerous enemies are vanishingly rare, so there’s little reason to get a gun. Most enemies have no ranged attack worth mentioning, and are too slow to pursue a fast character. The few enemies that are fast enough to reliably chase you are not particularly numerous and die easily to skinflint wooden arrows, with extremely rare exceptions.

[Goober]

Well, the reason that arrows work well right now is that damage is generic and linearly applied. In reality, timely arrow kills require penetration of vitals such as major arteries, lungs, heart.

A zombie based on black goop should be a decentralized system and about as easy to kill with arrows as a well organized vapor. Bullets would work the same way except they are designed to change shape when they encounter resistance, giving them a higher volume of effect at the target site.