# Realistic Speeds and Drop of Bullets Over Time

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Hey everyone, after seeing some pretty bad errors in bullet speed and bullet drop and that sort of thing lately, I have found one of the best comparison and trajectory websites to help all of you developers find out the average speed and drop of some common ammunition types.

http://www.shooterscalculator.com

Another thing that game developers should take into account is the ideal distance for the speed the bullet has traveled at. Most games just have the maximum damage right after the bullet leaves the barrel, but that generally isn't the ideal range for doing the most damage. Here are a few factors you should know when you take bullet drop and bullet speed into account:

1.)    A slower bullet speed will often do more damage to tissue, whereas a faster speed will often result in the bullet passing cleanly through the body. Faster bullet speed however will pierce armor much better than slower rounds, so there is an advantage to both high velocity rounds or low velocity rounds depending on your situation. A good source for determining the muzzle energy is right here:

However, the formula they use here ( Ek = (1/2)*(mv)2 ) is only good when you know the velocity of the bullet. If you use this in combination with the shooters calculator i mentioned earlier, then you can find the speed of any round at any distance you want.

2.) Don't be one of those developers that makes it so that the netcode favors those who have a high ping. One of the biggest errors I have seen is that they will make it optimized for those who have 150-200 millisecond ping. Make it below 150, because if you don't, your calculations will be thrown off and you will be unable to properly take advantage of your realistic bullet physics. The reason for this is that once people have a bit past one tenth of a second, you will begin to experience burst damage, and death behind cover. Based on the average speeds of some common game catridges, such as the 5.56mm NATO (Used in the M16 or M4 platforms), or 9mm Luger (Used in majority of handguns and some PDWs), you would have to bee within 330 feet aimed on the person for the 5.56, or 117 feet for the 9mm. Once you are outside of this range, the lag of the person who has the bad ping will make it so that they might not be where it looks like they are, thereby causing you to miss. Every single person will have some form of lag, but make sure it favors those whose ping is decent. If you don't, people will be frustrated by your game mechanics and you will most likely get bad media coverage and lose sales. The reason I chose these cartridges is that they are the two most popular firearm calibers we currently have, and almost every modern shooter uses them as a primary part of their product.

3.) Take barrel length into account. As a good rule of thumb, figure 50 feet per second, plus or minus, for every inch longer or shorter than a 22 inch barrel. You can find more information on rifle accuracy with this link, if you want to get really involved with your game

http://www.chuckhawks.com/rifle_barrel.htm

Anyways, I hope this helps you guys with your quest to make a great game!

-Sgt Andrew

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There is a lot more to it then your simplistic write up honestly.  And you're actually over simplifying things a lot.  There are actually more than a few quite accurate simulations out there.  Arma 3 has a few mods that bring in high accurate modeling for long range shooting.

Quite a few games are not even meant to be semi-realistic.  Most call of duty style games have always been more arcade-ish.  Few people want ultra realistic.  Also, most programmers have a math background either from university or what they pick up in coding.  Doing accurate bullet fall/travel is rather easy to be honest.

Most people are going for fun and learn the game systems they're playing in and adapt to them.  I do not see realistic shooters selling well period to be honest either.  Few games express the fact that a suppressor on a rifle increases range and on average speed of the projectile either.  In Counter-Strike Source/GO last time I played it actually made the rifle less dangerous but quieter, so it's a trade off for the player to decide which they want more.

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The bit about netcode isn't really how that works, so besides that..

As a fan of the genre, I am going to bookmark your links :D

Most games actually use instant hit projectiles instead of having any travel time at all :(

The ones with travel time probably are missing other features from their sims too, such as air pressure, temperature, turbulence, bullet tumbling and air speed...
All of them that I know of are missing a realistic damage model that differentiates between an intestinal puncture and a liver puncture...

Even "realistic" games are a balance between authentic subject matter, and unconstrained game design trying to create something "fun". Otherwise they wouldn't be games, they'd just be simulations.

Lastly, almost every gun-based game sounds wrong. How many games bother stimulating the speed of sound, or the sonic boom "crack" that a supersonic projectile makes as it travels past you - offset 90 degrees from the direction of the shooter...?
People don't want guns to sound real, they want them to sound like guns on TV. Even in the US where experience with military weapons is common, Joe Public still wants his games to sound like how Hollywood thinks guns should sound... Joe Public also wants to continue fighting after being shot in the guts instead of watching a simulation of sepsis... And he wants his bullet drop to "feel good", not be authentic.

There's a business case and an artistic argument as to why authenticity is given the middle finger. You talk about losing sales, but all of these other factors are just as interconnected.
Sure, if you make a completely authentic gunplay simulation then you probably will get yourself an extremely dedicated fan base made up of the kinds of people who play mil-sims like Arma, but that's a niche audience. Games like COD or Battlefield will never choose authenticity over mass-market appeal because they are mass-market products.

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The technological gap between good and crude ballistic algorithms is negligible compared to the gap between hitting instantly and actually simulating a bullet. Maximum accuracy is within everyone's budget.

I think there's an important user interface problem making realistic simulation of bullet trajectories quite irrelevant: most shooting games are intense action games, in which the player cannot reason too much about aiming and therefore

• either aiming is simplified by showing a virtual crosshair, which must take into account many factors about which the player has insufficient information (wind, exact distances and height difference)
• or the player only takes point blank shoots, in which the difficulty comes from moving targets

In the first case automatic assistance needs to compensate and hide most complexities of where the bullet will land; in the second case the difference between a rough simulation and a perfect one is negligible.

The place for appreciating good ballistic simulations would be a game of long range target shooting or sniping with unrealistic levels of information about wind, air pressure etc.; but someone who would like such a game would probably prefer to go out and shoot real guns.

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Thanks for the feedback guys! I may not be the best programmer, but I do understand shooting physics pretty well, so I'll keep making posts related to this. I do realize that complete authenticity sometimes hurts gameplay, but I believe that developers can find a good middle ground

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why 220 m/s with 10 gr bullet says it has 16 Joules, when with Ek = (mv^2)/2 i get 242 i clearly dont get something

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i clearly dont get something

Oh, the fun of obsolete units. They use grains (gr) not grams (g). 1 gram is about 15.43236 grains. If you put in 721.785 fps and 154.3236 grains the result is 242 Joules (179 foot-pounds).

Edited by kolrabi

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