Combining Ballistics, Attachments, Upkeep, Storage, Crafting, and Skills into a Coherent Combat System (CCS).

[SpudmanWP 27]

Combining Ballistics, Attachments, Upkeep, Storage, Crafting, and Skills into a Coherent Combat System (CCS).

OK, I have been playing for a couple of weeks, have review a bunch of the Dev Blogs, and have read some of the posts here. I had some thoughts that I wanted to share on a system that ties in several aspects of DayZ into a way to calculate combat damage and hit probability.

Background: I am a US Army Vet, am a database programmer, and am a Firearms enthusiast.

------ First up, Ballistics:

As many have said, assigning arbitrary values to large groups of weapons (all M-4/16s having the same value), ignoring range and bullet slowdown, damage that does not match real world values (303 and 7.62 Nato are very similar yet DayZ has 7.62 Nato 16% higher), completely absurd values (the VSS being a 1-shot kill while subsonic or the AS50), etc make the choice of weapons not mean much and they lack charecter.

How about implementing a true ballistics calculator to calculate impact energy, bullet drop at range, and drift (a function of MOA). This way a weapon’s damage is based in fact rather than assumptions.

Different bullets would also affect impact energy (besides just having a different drag coefficient). Hollow point & “tumbling” bullets would impart a greater amount of damage than the energy implies.

This would also allow bullets to do less damage at long range. A 9mm at 200 meters is a lot less than 10 meters.

Calculations do not have to be made as each bullet is fired. The basic calculations (impact energy & bullet drop at each range) would be made for every meter for X number of meters and stored as fixed values. Drift would be calculated once per shot (X percentage of MOA at degree Y) and would deviate from the aim-point more as the range increases. Later, wind can be added to this calculation.

Here is a good place to start: http://gundata.org/bullet-database/

------Next part, Attachments.

What?? You mean they serve a purpose other than looking cool and high-speed? B)

Attachments and how they are used will modify the calculations above. A foregrip will allow for a more stable aim when walking yet have no affect prone. A bipod is the opposite (good for prone but not walking). Combo foregrip/bipod does both. A stock on a sub-machine gun or rifle allows for more stable aim when using the gun’s sights. A laser should show the aim point on the target just like in RL. Optics & flashlights = obvious.

------Upkeep

If you plan on Cleaning Kits, then the effect of using them (or not) changes the ballistics calculations above. Introduce jams when you do not clean enough.

Vary the jam rate depending on the weapon as AKs laugh at dirt while M-16s are a bit more finicky. The tradeoff is that M-16s are more accurate (smaller MOA hence less drift).

------Storage

Do away with the slot-based system. How does a bandage take up the same space as a water bottle? An antibiotic shot/pill the same space as a can of coke? A pistol more space than a Jerrycan?

We should move to a weight based system with a few caveats. Packs should be weight limited, not slot limited. For small packs, no rifle can be stored. For medium sized packs, only one rifle (in addition to a slung rifle) can be stored and it should be attached to the left side of the pack on the outside (within full view). Large packs can carry two (one on the left and one on the back).

The larger the pack and the fuller it is should mean the harder & slower it is to run, roll or crawl. A guy with a Coyote pack loaded to the gills should be slower than a guy with a small pack.

Health & illness should also play a part in movement.

------Crafting

The ability to tune, modify, etc you gun and the ability to recycle/handload ammo (take the primer, powder, & bullet from a 7.62x39 and reload some 7.62x51, melt buckshot to make slugs, etc)

------Skills:

Not sure if you are planning a skill system, but if you do then being better at shooting, running, carrying, etc affect the above calculations.

The Key Point being to start with RL ballistic data and build up from there. Account for your health, your weapon’s health, the range, and the bullet type to vary the impact energy. Just for the love of God do not make the damage the same at every range.

Thoughts?

[Jalen 7]

I thought they were implementing just about all of this except perhaps the more detailed ballistics system.

[-Gews- 7443]

ignoring range and bullet slowdown

Bullets do slow down and they tried to match it with real-world ballistics, eg: half velocity = half damage.

As many have said, assigning arbitrary values to large groups of weapons (all M-4/16s having the same value)... ..damage that does not match real world values (303 and 7.62 Nato are very similar yet DayZ has 7.62 Nato 16% higher), completely absurd values (the VSS being a 1-shot kill while subsonic or the AS50)

True, some weapons are significantly more powerful for no reason at all, it's nonsensical. I don't think damage should have such big variations between calibers.

Hollow point & “tumbling” bullets would impart a greater amount of damage than the energy implies.

I'm trying to make edit some hunting rifles right now, I realized one problem with making expanding ammo more damaging is that it will do more damage to everything, vehicles included. Also it opens up a can of worms when deciding on damage values... does expanding ammo have twice the effect? Then expanding 7.62x39 is still only as powerful as FMJ 7.62 NATO... but if it is higher, everything is a one-shot kill... etc. Damage should be looked at being modified more.

The larger the pack and the fuller it is should mean the harder & slower it is to run, roll or crawl. A guy with a Coyote pack loaded to the gills should be slower than a guy with a small pack.

Agreed, it would also give people a reason to choose something like an AK-74 or an M4 over an M14 or DMR. Can carry more ammo for the same weight = don't need as much food and can run faster.

Attachments and how they are used will modify the calculations above. A foregrip will allow for a more stable aim when walking yet have no affect prone. A bipod is the opposite (good for prone but not walking). Combo foregrip/bipod does both.

I would like a bipod system.

[applejaxc 2500]

Are you sure you read all the devblogs? 'cause it seems quite a bit of your post has already been addressed.

[Chaingunfighter 917]

Agreed, it would also give people a reason to choose something like an AK-74 or an M4 over an M14 or DMR. Can carry more ammo for the same weight = don't need as much food and can run faster.

I don't know, the M14 is still a beast rifle. I actually really dislike the DMR, mainly because I'm not a huge sniping fanatic, but then again, the DMR is really just a heavily-modified M14 anyway.

It's probably my favorite weapon in the game, I really hope the M-14 stays (Albeit with the new attachment system, it could work much better with regular iron sights or the like instead of just the lackluster aimpoint that was made a requirement in Arrowhead.)

And, as been said before, most of this is going to be implemented or has been discussed as a possibility in the future.

I think the biggest thing I agree with is the storage idea.

I wish it were possible for there to be a better mechanic, instead of just slots, it could fit as much that was in a certain space, but coding something like that would be extremely difficult (You'd need the volume, length, width and flexibility of the object, as well as the same values for every object inside the container, and calculating when or when not you could add certain items.)

It sucks that good ideas can't always be implemented.

Edited May 21, 2013 by Chaingunfighter

[SpudmanWP 27]

Are you sure you read all the devblogs? 'cause it seems quite a bit of your post has already been addressed.

Yes and no. There is just too much to go over and I was trying to put it all in one place and show how the different aspects would affect each other.

Bullets do slow down and they tried to match it with real-world ballistics, eg: half velocity = half damage.

There is no reason to arbitraily decide that number when the formula is simple.

energy = 1/2mv^2 where m = bullet mass and v = velocity.

Just deviding it in half does not work.

Lets take a 10 gram bullet going 800 mps

As you can see, impact energy drops by the square of the velocity drop. At half velocity the energy is 25% of the original.

I'm trying to make edit some hunting rifles right now, I realized one problem with making expanding ammo more damaging is that it will do more damage to everything, vehicles included.

While that may be the case with the mod, SA may be different. In either case, I was just showing how it would plug into the CCS. Don't forget that HP bullets woulld have a negative AP value. Edited May 21, 2013 by SpudmanWP

[-Gews- 7443]

As you can see, impact energy drops by the square of the velocity drop. At half velocity the energy is 25% of the original.

This is true, however this would mean that 7.62x39 damage would look like this:

000m: 4,500

200m: 2,030

400m: 917

As you can see, at a mere 400 meters it would do very little damage. Currently at 400 meters it still does over 2,000 damage, not much but still a threat.

In real life the round would still be going 1200-1300 ft/s at 400 meters with only a quarter of the initial energy. However I doubt it would be 1/4 as effective. Going by velocity (momentum), it has roughly half remaining, which I feel is a better correlation with actual "damage" or effect.

Neither is perfect, but as long as a certain bullet has sufficient energy to penetrate a human and destroy or damage vital organs (at 400 meters a 7.62x39 is still like a hot 9mm point-blank) I doubt you will see massive variations in actual effectiveness.

Edit:

Another example would be .45-70, 405 grains at 1,330 ft/s = 1,590 ft-lbs. Right now this would work out to the same damage as a 7.62x39 FMJ....

(they use energy to calculate the initial damage, but damage drop-off corresponds to bullet velocity)

Obviously a .45-70 will do more damage than a wee 7.62x39 FMJ, but unfortunately the game doesn't take caliber into account either (although modders can simply alter the damage value).

Edited May 21, 2013 by Gews

[JKing (DayZ) 3]

All of this is pretty cool, You have earned my beans, sir!

[Mullraugh 1151]

True, some weapons are significantly more powerful for no reason at all, it's nonsensical. I don't think damage should have such big variations between calibers.

The reason the VSS and the AS50 are more powerful is because they're meant for taking out armoured vehicles. Everyone in DayZ just misuses them.

[-Gews- 7443]

The reason the VSS and the AS50 are more powerful is because they're meant for taking out armoured vehicles. Everyone in DayZ just misuses them.

The VSS fires a round with under 500 ft-lbs of energy. It's not even armor-piercing (SP-5). It's powerful because [a] it's bugged or someone made a "gamey" decision.

The AS50 is 5 times as powerful as an M107 because [a] it's bugged or someone made a "gamey" decision.

Edited May 21, 2013 by Gews

[SpudmanWP 27]

Its a combination of energy and frontal area (hello HP) that determines damage.

The reason that you start with impact energy is that it can be accurately calculated and is not arbitrary.

The "VSS" I spoke of was the "VSS Vintorez" which is a 9mm subsonic round.

btw, Where did you get the stats on the 7.62x39? What I found shows only a 66% drop in energy at 400m.

When speaking of the AS50, I was talking about the disparity of damage when comparing the two different types of ammo (5x the damage vs M107 dmg despite the same caliber per wiki).

[-Gews- 7443]

The reason that you start with impact energy is that it can be accurately calculated and is not arbitrary.

True, I don't like arbitrary damage. Ideally I would like "base damage" to be based on the projectile's weight, design, and size, and then modify that by velocity / energy.

btw, Where did you get the stats on the 7.62x39? What I found shows only a 66% drop in energy at 400m.

Extrapolated G1/G5 ballistic coefficient from Doppler radar tests done at Yuma Proving Ground.

122-grain M43 fired from SKS.

Muzzle velocity = 2,388 ft/s

200 meters = 1,804 ft/s

400 meters = 1,276 ft/s

1000 meters = 750 ft/s

Edited May 22, 2013 by Gews

[SpudmanWP 27]

Even at 500 meters the 7.62x39 Russian retains more energy than a 9mm or .45 FMJ at point blank.

It's still very lethal.

Edited May 23, 2013 by SpudmanWP

[enforcer1975 1111]

The VSS fires a round with under 500 ft-lbs of energy. It's not even armor-piercing (SP-5). It's powerful because [a] it's bugged or someone made a "gamey" decision.

The AS50 is 5 times as powerful as an M107 because [a] it's bugged or someone made a "gamey" decision.

http://en.wikipedia....org/wiki/9×39mm Afaik the bullet was designed with that in mind, at least for the technology of that time in mind. It might still be able to penetrate modern military armor. Only because it's slow doesn't mean it's weak, mass is also a factor and ballistics never is what you think might happen when just tossing numbers.

Edited May 23, 2013 by Enforcer

[SpudmanWP 27]

Velocity counts more for calculating muzzle energy than mass.

The formula is 1/2MV². That is half the mass multiplied by the square of the velocity.

Lets look at two Russian loads, the 9x39 and the 7.62x39 as it shows the same case size. The 7.62 load has a least 3 times the muzzle energy as the subsonic 9x39 yet in DayZ the 9x39 is upwards of 3 times more blood loss. This is severly out of wack.

Put it this way, if this were true then assault rifles would be going with large heavy rounds instead of small fast ones.

Don't get me wong, there is a benefit to a large heavy round in certain situations like subsonic use as you are velocity limited so putting as much mass behind it makes sense.

[-Gews- 7443]

Only because it's slow doesn't mean it's weak, mass is also a factor and ballistics never is what you think might happen when just tossing numbers.

The SP-5 round was not designed to penetrate armour. ArmA specifically uses the SP-5.

Nobody's saying it's ineffective. There's just no way it's anywhere near as powerful as it's currently portrayed as.

[enforcer1975 1111]

The SP-5 round was not designed to penetrate armour. ArmA specifically uses the SP-5.

Nobody's saying it's ineffective. There's just no way it's anywhere near as powerful as it's currently portrayed as.

Same with the AS50 ammo...i think it should be HEAP-I that why it does that kind of damage...I wonder why they made an extra ammo class for that.

[-Gews- 7443]

Same with the AS50 ammo...i think it should be HEAP-I that why it does that kind of damage...I wonder why they made an extra ammo class for that.

It's not explosive ammo, it has no explosive damage value like other explosive ammo. It was a bad decision by someone and needs changing.

Here's the damage 12.7x108mm APHE does:

127x108_APHE

hit = 24;

indirectHit = 5;

If the round was supposed to be explosive it would do similar to that (and in ArmA 2, 12.7x108 is portrayed as slightly more powerful than 12.7x99).

[enforcer1975 1111]

HEAP-I doesn't mean it make a big fireball like a tank shell. I'm talking about the small scale .50 http://en.wikipedia.org/wiki/High_Explosive_Incendiary/Armor_Piercing_Ammunition Maybe they gave the ArmA brits interesting ammo so people would favor it over the M107. Or it has something to do with the incompatibility of ArmA 2 and OA vehicles damagewise or the ballistics was different so they had to come up with an idea...voila the AS50 ammo was born. About the 9x39 i wasn't reffering only to the SP-5 but the ammo as whole, a slow slug can still pack a punch for the purpose it was intended to otherwise that round wouldn't have been so popular.

[-Gews- 7443]

HEAP-I doesn't mean it make a big fireball like a tank shell. I'm talking about the small scale .50 http://en.wikipedia....cing_Ammunition Maybe they gave the ArmA brits interesting ammo so people would favor it over the M107. Or it has something to do with the incompatibility of ArmA 2 and OA vehicles damagewise or the ballistics was different so they had to come up with an idea...voila the AS50 ammo was born.

Yes, APHE = HEAP. 12.7x108 and 12.7x99 are very similar in terms of power.

Anyways if I'm honest I think the reason the AS50 does that much more was purely to play to people's Hollywood expectations. There's no logical explanation.

About the 9x39 i wasn't reffering only to the SP-5 but the ammo as whole, a slow slug can still pack a punch for the purpose it was intended to otherwise that round wouldn't have been so popular.

Yes... it does pack a punch, like I said weights, velocities and energies are similar to a .45 ACP. No one would say a .45 doesn't pack a punch. The 9x39 is the best they could do while staying subsonic, however it's not nearly as powerful as full-sized rifle rounds. The damage value is too high as is, but then add to that the fact it appears to be bugged due to a wrong velocity value (does twice as much damage as originally intended, over 18000)...