Bullet physics and gun limitations.

[Toybox 36]

Hi all,

I was just wondering if anyone understands the bullet physics on this game? Do the weapons suffer from bullet drop as in RL? How far can you really shoot with a pistol compared to a rifle or sniper rifle? I'm sure its not a case of "If you can see it, you can shoot it" But it would be nice to understand when compensation for a well placed shot.

Cheers guys!

[sidwulf 69]

This has me thinking.

The ARMA II engine strives to be realistic with projectile physics but i find it strange that the M9 does not hit exactly where the iron sites are pointed. Is this inaccuracy realistic? I would assume the iron sites would be dead on at close range. Random bullet spread (RBS) for semi auto when iron sites are involved is a terrible idea. I am afraid that kind of implentation has happened here.

[Tallpoppy 19]

yes. please use any popular or not so popular search engine typing these words in carefully dayz wiki weapons

[7-75 callaghan 43]

Hi all' date='

I was just wondering if anyone understands the bullet physics on this game? Do the weapons suffer from bullet drop as in RL? How far can you really shoot with a pistol compared to a rifle or sniper rifle? I'm sure its not a case of "If you can see it, you can shoot it" But it would be nice to understand when compensation for a well placed shot.

Cheers guys!

[/quote']

Arma 2 (arma series in general) has the most realistic ballistic simulation publicly available. So yeah, it has bullet drop. Some weapons have adjustable sights, and others are zeroed to a set distance. This means if you have a weapon zeroed at 300m, you often have to aim below the target point to hit it, practice in single player missions to experiment/the armoury mode.

The bullets have different parabolic curves depending on mass and muzzle velocity etc. - they follow a bell trajectory, meaning that some rounds actually 'hop-up' a little after they leave the barrel before coming back down on the target. This is especially true of the subsonic rounds used for suppressed weapons.

The bullet slows down as it is resisted by air friction and gravity, meaning that the further the target is, the less damage will be delivered. They also have a 'spread' - again depending on the quality of the weapon, muzzle velocity, barrel length etc.

Honestly, you could have made a little effort to research what product you were buying, i.e. a military simulator, but anyway.

Iron sights would not be 'dead on' at close range, no, it depends on the weapon zero-point.

As for range. Do your own research on the weapons in ArmA 2. Don't mean to sound rude, but c'mon guys, that is sheer laziness.

[dsi24 227]

This is an informative thread.

And here is a good post.

BF has bullet drop' date=' and that's it. I very much doubt that it is realistic bullet drop, rather than simple linear gravity tailored to the size of the small maps.

Arma ballistics have the folllowing:

-Bullets are fired from the chamber of the gun, not the barrel, the sightline, or the crosshair as is usual in FPS.

-Bullets can ricochet with a variety of speeds and angles

-The speed and direction of bullets is affected by object penetration

-Sights and scopes have correct zeroing, meaning that the bullet is lobbed upwards in a parabolic arc, rising up the the line of sight (typically) at 50 meters, and traveling above it until it 'falls' into' the sight line at 300 meters. This is the most important aspect that affects your shooting performance, and it is why your uber leet FPS players are missing perfect headshots at 200 meters.

I have never heard of any commercial game with the following features, but i may be wrong. Most of the time these features are only found in ultra-realistic mods for counter strike, quake and PC games like that.[/quote']

I don't think DayZ has it, but ACE adds wind to the game as well, which further affects long range accuracy, and even how you use smoke grenades.

[lev 39]

Admittedly I have never fired a gun in real life so I don't know if the handling is realistic so I will give the BIS guys the benefit of doubt here. We'll need an actual expert in guns to weigh in on this.

However, with regards to how bullet physics work in Arma, I can give some info. All bullets have bullet drop and different weapons suffer a different amount. Pistols are very accurate up to ~40m and then hitting targets become much harder. Assault rifles (most are zero-ed at 300m) are good up to about 400m where it becomes more difficult to hit targets. Sniper rifles are good for up to the range they can be zero-ed at and then afterwards it becomes harder.

Edit: I should probably clarify what I mean by "good up to". I generally mean this for a stand still target where you don't have to compensate much for the zero-ing on the sights. So you can put your cross-hair or iron sights directly on, or covering the target and rest assured that you have hit your target. Above the ranges I specified above, you will have to watch where the bullet hits and then compensate.

@Sidwulf:

I have not found the M9 to be that inaccurate. At close ranges the iron sights are basically dead on. As far as I know RBS is not implemented for any gun. Even if you do not sight in, the bullets land where the gun is pointing; it's just harder to tell where you are aiming without sighting in.

[racecar 0]

Windage is strictly an ACE thing.

Also, the descriptions of bullet behavior in this thread are not exactly accurate. Bullets to not travel upward in releation to the angle they were fired, they only travel downward as they are affected by gravity.

Sights are zeroed to a certain range, which has them pointing at a point below the level of the barrel to compensate for bullet drop. This makes it appear that bullets "hop-up" in relation to the barrel, when in fact they just haven't fallen as far as the sights are pointing.

Edit: Nevermind people posted better links. I'm not sure whether the ballistics simulated in ARMA II are accurate to real life, but ballistics are simulated.

[7-75 callaghan 43]

Windage is strictly an ACE thing.

Also' date=' the descriptions of bullet behavior in this thread are not exactly accurate. Bullets to not travel upward in releation to the angle they were fired, they only travel downward as they are affected by gravity.

Sights are zeroed to a certain range, which has them pointing at a point below the level of the barrel to compensate for bullet drop. This makes it appear that bullets "hop-up" in relation to the barrel, when in fact they just haven't fallen as far as the sights are pointing.

Illustrative image incoming...

[/quote']

Actually windage is hard-coded into the game, as the 'windresistanceCoeficcient', but is disabled in the vanilla game. ACE simply re-activates it. It is present as active in VBS 1 and 2 of course.

This ballistics stuff is pretty well known about ArmA 2 actually, and can be found on any site that goes into the details.

[(gp)echo 0]

Hi all' date='

I was just wondering if anyone understands the bullet physics on this game? Do the weapons suffer from bullet drop as in RL? How far can you really shoot with a pistol compared to a rifle or sniper rifle? I'm sure its not a case of "If you can see it, you can shoot it" But it would be nice to understand when compensation for a well placed shot.

Cheers guys!

[/quote']

Arma 2/Day Z uses more advanced external ballistics than you might expect. Although I recommend you search existing threads, here is a brief summary:

- bullets experience two primary forces: gravity and Newton drag (speed-squared)

- bullets are not subject to wind drift

- bullets do experience bullet drop comparable to their real-world counterparts.

- weapons are zeroed for a designated range; some allow manual adjustments to this zero range

- the mil-dot sights on many sniper rifles allow for relatively accurate target ranging and holdover corrections

If you want to take advantage of this knowledge, check out the following articles:

http://en.wikipedia.org/wiki/External_ballistics

http://en.wikipedia.org/wiki/Rifleman's_rule

http://www.frfrogspad.com/extbal.htm

[wufnu 0]

Honestly' date=' you could have made a little effort to research what product you were buying, i.e. a military simulator, but anyway.[/quote']

My thought process was like this: "Wow, this sandbox zombie game looks amazingly fun! What's Arma II? The real question is, who cares? *purchase*" I had the mod downloaded before the game. Of course, I later played through the game and thought it was great but it's reasonable to imagine someone buying Arma II for DayZ without knowing the full scope of what the Arma series is all about.

[(gp)echo 0]

The bullets have different parabolic curves depending on mass and muzzle velocity etc. - they follow a bell trajectory' date=' meaning that some rounds actually 'hop-up' a little after they leave the barrel before coming back down on the target. This is especially true of the subsonic rounds used for suppressed weapons.

[/quote']

For someone displaying frustration at the ignorance of the OP, I would expect more.

The "hop-up" portion of your paragraph above is terribly misleading. A bullet never rises above the bore line. Rather, it's trajectory relative to the sight line appears to rise during a portion of the bullet's flight. This relative, not absolute, rise gives us the near and far zero ranges that allow us to compensate for bullet drop more accurately at long ranges.

The "dropping" of a bullet onto the target arises from the need to elevate the bore line slightly above the horizontal/sight line (assuming the target is at the same height as the rifle). At no time does the bullet "hop-up" above the bore line in a non-stochastic fashion.

If I misunderstood your intent/wording, then disregard the above. ;)

[Toybox 36]

WOW,

So I was totally unaware that I needed a degree In physics and ballistics to play this game not to mention the complete understanding of the realness the ARMA series was so clearly based upon.

Again my apologies for being such an ignorant player. It was a simple question which asked for a simple answer, not a break down of the physics surrounding the RL parameters of firing a bullet through earth's atmosphere.

What was I thinking, asking a question like that amongst what seems to be every gun toting, military personals passion in their spare time, so for those of you that like to speak down those that don't own or understand this sort of thing, please get over your self!

So, yes as Wufnu said, I to didn't care for the realism of the game either, I purchased for a fun, different game Idea, I just wanted to know for when I line something up in a sniper rifle I don't waste 20 rounds and wonder why I cant hit anything.

[aoshi 32]

if i shot a target above me, the gravity will affect more, and below? affect less?

zeroing count only for horizon line?

[elk123 0]

What about wind or the Coriolis affect?