Bullet velocity - inaccurate ?

[Inkompetent 0]

Everything falls at the same rate, a piece of paper falls at the same rate as a car.

In 100% vacuum - yes. You forgot air friction. The aerodynamics of a bullet are quite important for its flight characteristics. Different shape, muzzle velocity, mass, and center of mass will give different ballistics.

[maturin 12]

Were you hitting prone people?

[Panzer Jager 10]

Damage drops over distance. 7.62x54 and 7.62x51 weapons in ArmA 2 do not distinguish different types of ammunition (such as 7N14 from Type L or M118LR from M80.)

This means that at very long ranges it's going to take multiple shots to kill a target with an SVD or even an M24, as opposed to if one were to add new types of ammuntion such as 7.62x51 M118LR OTM, which creates larger wound channels and suffers less loss in velocity.

Since velocity affects how much damage is done by a projectile in ArmA 2, you will find that at 600m or longer ranges, an SVD or similar calibre weapons will need 2 or more torso hits. Large calibre (12.7mm) weapons have practically infinite 1-hit range, and interestingly so does the 9x39 VSS, although it is very difficult to aim beyond 400m.

On a side note, ArmA 2 does not properly incorporate muzzle velocities based on barrel length - although ACE has a work-around, the unmodded game has all weapons in 5.56x45 weapons at 900m/s (when weapons like the G36C and XM8 Compact should be firing at a significantly lower ~770m/s.) Similar story with 7.62x51, where the game has very short-barrel weapons like the Mk17 CQC and FAL Para (compared to the M240) which fire at much higher velocities than they should be.

Edited July 13, 2010 by Panzer Jager

[cartier90 0]

Id just like to bump this thread - any progress made ?.

Edited July 21, 2010 by cartier90

[cartier90 0]

Shameless bumping again - Any news or progress ?.

Edited August 24, 2010 by cartier90

[cartier90 0]

Any progress at all on this issue

http://dev-heaven.net/issues/show/8219.

I dont quite understand the update 14 days ago.

[carlostex 38]

I´m glad i found this problem is on the issue tracker.

All BIS have to do is to add possibility to define initspeed in the class weapon instead of class magazine. I don´t how difficult this would be to the developers but it would allow for better simulation i believe.

In OFP each weapon had its own Magazine classname so this problem was not an issue at that time. Only the fact that we couldn´t use a M16 mag on a M4.

SO maybe it´s the time to correct this, by defining at the class weapon instead at the magazine. Weapon barrels have a much greater impact on projectile velocity than magazines.

[max power 21]

Weapon barrels have a much greater impact on projectile velocity than magazines.

Well, if you have a magazine of low pressure load cartridges with a heavy bullet for subsonic applications, I think that is the greater factor. Barrel length does have an effect but it's not so great until there is a huge difference in length. The m4a1 with its 14.5 inch barrel has a muzzle velocity of 880 m/s, and the m16's 20 inch barrel produces a muzzle velocity of 940 m/s. The m4's 72.5% barrel length yields 93% of the muzzle velocity when compared to the m16.

[galzohar 31]

Well most weapons of the same caliber fire the same rounds, so usually it's the barrel length being the most significant factor since you use the same bullets. Subsonic ammunition is the special case where ammunition matters, not the normal case where barrel length is the important factor (since there is no bullet type factor in the normal case).

ACE already made a rather proper fix for all of this, really wish BIS did as well. Yet another reason to stick to ACE.

[max power 21]

Well most weapons of the same caliber fire the same rounds, so usually it's the barrel length being the most significant factor since you use the same bullets. Subsonic ammunition is the special case where ammunition matters, not the normal case where barrel length is the important factor (since there is no bullet type factor in the normal case).

ACE already made a rather proper fix for all of this, really wish BIS did as well. Yet another reason to stick to ACE.

Well, subsonic ammunition is really the only case I can really see as relevant in to ArmA gameplay. Perhaps you could think of an illustrative example where it makes all of the difference?

[galzohar 31]

I don't understand your question. My point was that the BIS system doesn't allow to make a difference between an M4 commando and an M16A4, which is very bad, and ACE works around that limitation.

[cartier90 0]

http://dev-heaven.net/issues/show/8219

The issue appears to be 'fixed' according to .50 cal - can anyone verify this - with latest patch I assume ?

[pooroldspike 129]

How do all you guys get on with Comb Ops silenced rifles?

Their muzz velocity is so slow and their trajectory so like a rainbow that I swear you can pull the trigger then go have a cup of tea and still be back in time to see the impact.

It's fun though to keep popping away at the enemy while they just stand there like sitting ducks because they can't hear the silenced weapons soft 'phut' and don't know they're being shot at til one goes down or somebody notices puffs of dust at their feet..:)

Are silenced rifles used much in the real life military?

How does their muzz vel compare to a 'proper' rifle?

And if the enemy is wearing a bulletproof vest, would a silenced round have the punch to go through it?

How do silencers work anyway? They look like thick cylinders on the end of the barrel, but what goes on inside?

[cartier90 0]

IRL - the very fittest of soldiers are known to be able to outrun SD rounds ........

;).

[Noraf 0]

I would think that silenced weaponds are rearly used by regular forces, special forces on the otherhand do frequently use them.

same goes for suppressed weaponds.

in a combat situation, i think i'd prefer the suppressed one over a silenced one, since you keep stoppingpower and range quite well, and it's range surpasses the supressed ones.

The difference in the ammo is usualy the amount of gunpowder in it. supressed rounds aren't different from regular ammo, but silenced needs to be subsonic

[Inkompetent 0]

Are silenced rifles used much in the real life military?

How does their muzz vel compare to a 'proper' rifle?

And if the enemy is wearing a bulletproof vest, would a silenced round have the punch to go through it?

How do silencers work anyway? They look like thick cylinders on the end of the barrel, but what goes on inside?

Properly silenced rifles are rarely used, since to be really silent you need subsonic rounds (ammunition that after passing the attached suppressor has a speed lower than sound), and for subsonic rounds who have a weaker propellant charge than ordinary ammunition you need a weapon modified to work with that little propellant (i.e. lighter bolt/weaker spring/adjusted gas valve).

After all that hassle you end up with a short range weapon, both in ballistic curve and stopping power/penetrative capability. There's a reason only special forces, during very special tasks, use this kind of weapons. They are most often useless.

As for muzzle velocity a subsonic round has to travel at less than roughly 340m/s. Usually lower than 330m/s to get some leeway for varying air temperature. That can be compared to 'ordinary' muzzle velocities of assault rifles usually being 750m/s or more. One compensates with a heavier bullet to retain stopping power, but it never fully compensates over distance.

How the most common rifle suppresor works (the variant I'll describe is made in all-steel, and is alled a 'reflex suppressor'. They usually last around 300.000 rounds for an assault rifle) is like a 'sleeve' you put over the barrel. Often you have at least half the length of the suppressor going back over the barrel, but that varies depending on weapon, barrel length, caliber, and other factors (for example the SOPMOD suppressor for the M4A1 SOPMOD has a very short sleeve to allow simultanous fitting of a M203 grenade launcher attachment).

At the front end of the suppressor you have several chambers separated by 'baffles' (think a metal membrane with a hole in the middle, where the inner edges are curved inwards towards the barrel). The more baffles you have, the more silent you get, but it also creates a heavier and longer suppressor.

The long 'sleeve'-part is an expansion chamber. This is where most of the gases from the muzzle will escape back into, drastically reducing the velocity of those gases once they finally leave the suppressor, and each baffle helps catching more of the remaining gas.

This actually has a lot of advantages. First the baffles sort of act like an extended barrel since the holes aren't that much wider than the bullet diameter, thus helping propel the bullet with the remaining gases and increase its muzzle velocity slightly more.

Secondarily the design of a reflex suppressor, thanks to reducing the violent force of gases behind the bullet actually reduces the muzzle-exit turbulence that usually screws up a bullet's precision (happens to all non-suppressed rifles), and thanks to that gives a somewhat better accuracy as well (only distinctively noticable at extreme ranges).

The most common use of suppressors though is with ordinary full-power ammunition. They are used to drastically reduce the muzzle flash, and to distort the sound of the shot to make it harder to identify *as* a shot, and to lower the sound frequency of the shot so much that it makes the shooter harder to locate by hearing (high frequencies are easy to pintpoint the direction too. Low frequencies are not). They are not supposed to make the shot silent.

However the bonuses of the suppressor comes with a drawback, in addition to the cost and extra weight/front-weight of the weapon, and that is that a suppressor shifts the weapon's zero. You won't hit in the same spot with a (reflex) suppressor as without. This is noticable even at as short distances as 50 meters. At 300m you probably wouldn't even hit your target if you aimed at him. This means that you have to re-zero your weapon if you want to use a suppressor, and thus mounting/dismounting a suppressor in the field would never be done unless necessary.

If you are a sniper you could of course transport the rifle without the suppressor mounted, but you would attach the suppressor when you prepare to shoot, since that's what your rifle is zeroed for.

However it appears that the benefits of using a suppressor aren't usually needed for a rank and file soldier, and thus the military avoids the expenses, and suppressors remain a special forces item since they perform the kind of operations where the use of a suppressor really matters (i.e. being hard to locate/identify as shooting). And even then a suppressor is actually a pretty special thing and its use depends a lot on the kind of mission.

Edited March 20, 2011 by Inkompetent

[celery 8]

I'm not sure if this is the topic, but is the 9x39mm round of the VSS Vintorez REALLY as powerful as a full velocity .50 cal round? The VSS and M107 in Arma 2 have nearly identical damage values (checkable with HandleDamage EH) at close range, and the VSS can even blow up armored vehicles. The only downside is next to no penetration capability.

[Inkompetent 0]

I'm not sure if this is the topic, but is the 9x39mm round of the VSS Vintorez REALLY as powerful as a full velocity .50 cal round? The VSS and M107 in Arma 2 have nearly identical damage values (checkable with HandleDamage EH) at close range, and the VSS can even blow up armored vehicles. The only downside is next to no penetration capability.

Against a soft target at short range I think the damage could probably be compared. A very heavy bullet for the 9x39 would be able to cause quite some tissue damage, while a .50 would over-penetrate. However I do think that it is indeed exaggerated in the game. Especially against armour. The low velocity bullet of the VSS is notoriously bad at penetrating anything, while the .50 is designed for it.

Edit: After checking some energy values and armour piercing capabilities the 9x39 SP-5 and SP-6 ammunition has about a third of the bullet weight of the .50, and a third of the muzzle velocity. Even with a steel core giving the SP-6 quite decent penetrating capabilities (punches through avarage (I'd estimate class III) body armour at 100-150 meters) it cannot anywhere, and I mean anywhere compare to a .50 as far as energy goes. And with a steel core the argument for effectiveness against soft targets goes straight out the window too.

Edited March 20, 2011 by Inkompetent

[galzohar 31]

I think VSS has too much damage in Arma ;)

Energy is usually not a very good measurement for damage, but when the difference in energy is THAT big it definitely means *something*...

[pooroldspike 129]

Thanks to Inkompetent for the great suppressed/silenced writeup..:)

[walker 0]

Hi all

Micro UCAVs will replace the sniper round and the sniper probably within less than a decade.

An army armed with micro UCAVs based on present day off the shelf technology could probably already wipe out even the US army in a matter of days.

Kind Regards walker

Edited March 21, 2011 by walker

[Beagle 684]

Hi all

Micro UCAVs will replace the sniper round and the sniper probably within less than a decade.

An army armed with micro UCAVs based on present day technology could probably already wipe out even the US army in a matter of days.

Kind Regards walker

Na I dotn think so, tzhe main reason why Sniper will see no futher action is the introduction of powered armour suits with integrated cloaking device and the indroduction of self target aquiring pulse phaser rifles..the technologie is in your digital camera right now. But war wil end soon anyway because there is no enemy nation left to bomb on united earth...were waitign for the Klingons.

Edited March 21, 2011 by Beagle

[walker 0]

Hi Beagle

I am 100% serious.

NATO has already gone one step further than this and is also actively researching and specifying the requirement's for NANO UAV’s.

Kind Regards walker

Edited March 21, 2011 by walker

[celery 8]

Hi all

Micro UCAVs will replace the sniper round and the sniper probably within less than a decade.

An army armed with micro UCAVs based on present day off the shelf technology could probably already wipe out even the US army in a matter of days.

Kind Regards walker

And how the hell does this have anything to do with the topic?

[Beagle 684]

Hi Beagle

I am 100% serious.

NATO has already gone one step further than this and is also actively researching and specifying the requirement's for NANO UAV’s.

Kind Regards walker

I'm serious too, cloaking technologie is on the way as well as remote and autonomous weapon systems and armour suits or using energy projection as a weapon. The only thing that can stop this for a while is the next world economy crisis in 4-5 Years. But unfortunately the Klingons wont show up..so no hope for a united earth movement.

Will will be stuck using all the shiny new killing methods at fellow human beeings.

Edited March 22, 2011 by Beagle