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Bullet speed
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Description

The bullet speed is too low.

A NATO 5.56x45 has a muzzle velocity of 1000m/s

On 300m the bullet should be almost immediately at the target.
Once i was able to avoid a sniper shot from about 400-500m, i just rolled left

Details

Legacy ID
4145077409
Severity
Minor
Resolution
Open
Reproducibility
Have Not Tried
Category
Other

Event Timeline

oldirty edited Steps To Reproduce. (Show Details)Mar 21 2013, 10:21 PM
oldirty edited Additional Information. (Show Details)
oldirty set Category to Other.
oldirty set Reproducibility to Have Not Tried.
oldirty set Severity to Minor.
oldirty set Resolution to Open.
oldirty set Legacy ID to 4145077409.May 7 2016, 12:58 PM

Skip to 1:21 ---- this is a 7mm. At 500 yards it's going 2000 feet per second/600-700m/s. AND YOU CAN SEE THE BULLET! Muzzle velocity is over 3000 fps/+-1000m/s. You can see the bullet at he's only shooting 470 or whatever yards. Bullets slow down VERY quickly. The further you shoot the slower the bullet will be by the time it reaches its target.

http://www.youtube.com/watch?v=fETxgVE2V3E

The speed of the bullets in ARMA3 is perfect.

@leechweed

  1. You dont see the bullet (only the upheated air and wave of that) the bullet is much faster

2 its not about if i can see it or not

3 a man runs 10 meter while a bullet travels 500m?

@oldirty

It doesn't matter if 5.56 can go 3000fps, by the time it gets to 500 meters it'll be going barely over 1/2 that speed. There is no instants with bullets.

If you're dodging bullets I'd say you've got awesome reflexes to see the sniper take a shot and dodge it. If you're already running and unless he's got a perfect lead on you there's no way that he's going to hit you. If you can run 1 or 2 feet in less time than it takes a bullet to travel 1/2 km you're not going to get hit.

Forget about the vapour trail too. Look at the snow where it hits, the bullet is literally in front of that trail.

well you dont aim exactly on a running man. a little in front of him, but not 10 meter!

In arma on 300m i can count to 1

In reallife on 300m, when i stroke my trigger just a little bit, my target is immedaitely hitted.

You dont realise that the bullet is much fast than any other thing that happnes in this time.

@oldirty

You know I'm sorry you might be right. After oodles of kintergarden math and lots of ARMA 3 tests I think that the average for 7.62 (leaving @ 2900 fps and at 500m being at about 1800 fps) would be about 2300 fps.

http://www.youtube.com/watch?v=clcsq-L51M4&feature=youtu.be

my stopwatch timing might suck but I'm getting about 1.6-1.8 seconds at 1922 feet. I'm not sure if the bullets start fast and slow down like they should but I'm averaging only 1061 fps.

So I tip my hat you and apologize. I'll change my vote :)

@leechweed

Thats maybe the problem. i guess at the time they fly all the time with same speed. So for that 1000m/s is way too fast.
But at the time it doesnt feel good.

zGuba added a subscriber: zGuba.May 7 2016, 12:58 PM
zGuba added a comment.May 8 2013, 8:36 PM

Do you realize that 5.56x45 shot with MV of 2900 fps / 883 mps loses almost half of its velocity after 300 yards? Average speed on this distance is about 660 m/s then. It will take ~ 0.4 sec to hit target at this distance. So when firing at man sprinting 7 m/s sideways to you you'll need to put ~ 3 m correction ahead of him.

The video is kinda wrong, you should rather register when the hit occured, not when man visibly collapsed.

@zGuba

Yes i do, and its not that bad on far range.

I found a good video.

http://www.youtube.com/watch?v=igXUZVWylsM

The first 400-500 yards are almost immediatly traveled, an then comes a massiv drop

zGuba added a comment.May 9 2013, 12:29 AM

The video is great but I'd rather see ballistics tables like this:

http://www.shootingtimes.com/wp-content/blogs.dir/11/files/6-5mm-grendel-the-round-the-military-ought-to-have/6-5mm-grendel_009.jpg

I did some more calcs. All are approximates of course, but shouldn't be worse than reality as I'm simply connecting the dots.

Time at 300 yards: ~ 0.4 seconds
Speed at 300 yards: ~ 433 m/s
Speed at 500 yards: ~ 295 m/s
Average speed: ~ 364 m/s

200 y = 182.88 m
182.88 m / 364 m/s = ~ 0.5 s (very roughly)

Added 0.4 TTF to 300 yards, it turns out that if your rifle features small muzzle velocity you should be satisfied with 0.9s time to flight to 500 yards. However if you shoot same round with longer barrel, it will reach target faster.

Remember weapon I refer to has a bit shorter barrel, the muzzle velocity is 883 m/s, not 1000 m/s!

Thank you for this very very nice table.

I dont understand what you are doing xD, but i calc it by myself and hmm...

5.6x

300 yards 0,47s

1000 yards 2,7556440248641s (very exactly xD)

In reallife this "looks" faster. Specailly the low range.

zGuba added a comment.May 9 2013, 9:48 AM

All is matter of scale :) Arma terrains are large and FoV settings are made so terrain features "feel" closer than they are.

Mass closing ancient tickets with no activity for > 12 months; assume fixed or too trivial.

If this issue is still relevant in current dev build, please re-post.