Home » SIRTECH CLASSICS » Jagged Alliance 2 » The A.I.M. Library » Real life Weapon Questions
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| Re: Real life Weapon Questions[message #167375]
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Wed, 12 December 2007 17:23  
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 foij |
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Messages:227
Registered:February 2007
Location: in a van, down by the riv... |
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NightLord
3. I'm still confused something about the whole calibre issue. Generally it is said the large the calibre the more powerful the shot. So why is a 9mm generally weaker then lets say a 5.56mm?
Can't help with the other points, but a cartridge has two critical dimensions, calibre and length. A 5.56x45mm FMJ rifle cartridge has a lot more propellant than a 9x19mm pistol cartridge. Hence, a 5.56 (.223 calibre) bullet has much more energy than a 9 mil.
Disregarding barrel length, etc., in another example, a 9x19mm round has much less energy than a 9x39mm round. Both are the same calibre, but the 9x39mm has higher energy (more propellant, etc.).
[Updated on: Wed, 12 December 2007 17:26] by Moderator Report message to a moderator
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Sergeant 1st Class
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| Re: Real life Weapon Questions[message #167377]
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Wed, 12 December 2007 17:41
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| cougar |
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Messages:254
Registered:March 2000 |
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The sonic bang is quite loud, it would definitely be heard over some distance.
Try to do a search on a video site (for example youtube.com), there should be some videos of suppressed weapons firing supersonic ammunition.
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Master Sergeant
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| Re: Real life Weapon Questions[message #167390]
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Wed, 12 December 2007 18:55
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| NightLord |
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Messages:7
Registered:December 2007 |
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Thx for the quick replys.
Another one for the calibre:
Ok, so what role does the calibre actually play? I guess the mass of the bullet is more important then the calibre, so why is everyone talking about calibre instead of (shotgun-style) weigt of the bullet?
I also guess that the bullet length is independent from the calibre - so why does calibre seems to be more important then length? (In generall everone is talking about calibre instead of mass or length).
@afp: thx a lot =)
@cougar: I already did  It is definetly loud, but Sonic bang is quite different from "normal" sound as I understand it. The overpressure runs out quite quickly.
I quote (this information can be found nearly everywhere about sonic booms):
"The intensity and width of a sonic boom path depends on the physical characteristics of the aircraft and how it is operated. In general, the greater an aircraft's altitude, the lower the overpressure on the ground. Greater altitude also increases the boom's lateral spread, exposing a wider area to the boom. Overpressures in the sonic boom impact area, however, will not be uniform. Boom intensity is greatest directly under the flight path, progressively weakening with greater horizontal distance away from the aircraft flight track.
Ground width of the boom exposure area is approximately one mile for each 1.000 feet of altitude; that is, an aircraft flying supersonic at 30.000 feet will create a lateral boom spread of about 30 miles. For steady supersonic flight, the boom is described as a carpet boom since it moves with the aircraft as it maintains supersonic speed and altitude."
So the point is if someone can hear the bang when standing around 60 feet away from the bullet's path?
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Private
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| Re: Real life Weapon Questions[message #167392]
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Wed, 12 December 2007 19:38
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| cougar |
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Messages:254
Registered:March 2000 |
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Im not a physics professor, but the crack of a whip is a supersonic bang and it can definitely be heard from 18 m (60 ft), so I guess the bullet could be heard but I guess theres people here that know the answer to this.
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Master Sergeant
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| Re: Real life Weapon Questions[message #167413]
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Wed, 12 December 2007 22:06
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| Starwalker |
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Messages:758
Registered:October 2005
Location: Hannover, Germany |
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A gun makes two to three noises:
1) mechanical noise (pin falling on cartridge [not that loud], reloading on semiautomatic guns)
2) the explosion of the propellant
3) the supersonic crack that occurs with that type of ammo. If the gun uses naturally subsonic ammo, this does not ocur.
No. 1 can be suppressed on very few guns with a locked bolt, so the normally semiauto gun does not reload itself (it also has more recoil that way).
No. 2 can be suppressed with a sound suppressor that slows the expanding gases down when they leave the barrel.
No. 3 cannot be suppressed, it can only be avoided by using subsonic ammo instead.
No. 1 and No. 2 occur at the location of the gun, No. 3 spreads from the flight path of the bullet.
So if you can suppress No. 1 and 2, but not 3, then everyone in the vicinity notices that a shot was fired, but it will be harder to locate the spot from which the shot came.
Unfortunately, this is not simulated in JA2, all noise from gunshots occurs at the loaction of the gun.
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| Re: Real life Weapon Questions[message #167424]
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Wed, 12 December 2007 23:37
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| afp |
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Messages:75
Registered:November 2007 |
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I'm not sure about all terms, but as far as I know it should be "flashbangs" equivalent. It's only light, sound and smoke, never heard about sucking oxygene...
But there are many models out there, some may be combined with all kind of gases like tear gas or other... so I suppose that such a gas may prevent breathing normally...
EDIT: Check this, some are combined with tear gas..so everything is possible:
http://www.eliteukforces.info/special-air-service/weapons/stun-grenade.php
"Modern stun grenades have evolved to detonate multiple times and can contain irritants such as CS or CN tear gas. SAS assaulters become gradually conditioned to the effects of flash-bangs during training. Their equipment also protects them : tinted eye pieces in SF-100 respirators protect against the flash and the respirator itself guards against the effects of the smoke and gas released by the grenades, whilst ear-plugs protect the trooper's hearing."
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Corporal
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| Re: Real life Weapon Questions[message #167507]
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Thu, 13 December 2007 20:18
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| afp |
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Messages:75
Registered:November 2007 |
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"I've red a couple of silencer tests with SUpersonic Ammo, but they all messure the sound from the muffle or 1m besides it. So from that I cannot say, if the sonic boom can still be heard from someone 20m+ besides the path of the bullet. "
I guess it depends, if in open or indoors, indoors for sure, if no obstacles or noise.
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Corporal
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| Re: Real life Weapon Questions[message #167739]
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Sun, 16 December 2007 07:03
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| Dr-D |
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Messages:102
Registered:July 2005
Location: Portugal |
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NightLord3. I'm still confused something about the whole calibre issue. Generally it is said the large the calibre the more powerful the shot. So why is a 9mm generally weaker then lets say a 5.56mm?
There are lots of things you can know about a bullet and how those things affect the results.
mass
caliber
length
quantity of gunpowder
bullet shape
so
speed = quantity of gunpowder * effectiveness of the gun / mass
energy = 1/2 speed^2 * mass
armor pricing capability = energy * bullet shape effectiveness / caliber
So with the same energy, a small caliber bullet will price the armor more easily.
thats why the rubber bullets used by the riot police are so large, so they have less piercing possibility's, but still delivering a huge impact energy.
But the smallest the bullet is the small the wound hole it makes. It will just go through.
SO what is AET:
AET is a bullet(the projectile only) shape that allows good armor pricing capability(high energy, small caliber), but it becomes highly unstable after 5cm(2inch) of perforation.
So the ATE bullet will go through the armor, after 5cm then inside the flesh it will tremble lousing all its energy to the sides, not to the front, preventing over-perforation.
This tremble causes massive wounds.
(an example: P90's ammo does this)
So whats the best silenced bullet:
to be silenced, a bullet needs to travel at less speed then the sound 340m/s.
The normal speed of an 5.56 bullet is 910 m/sec and has a mass of 4.01 gm
so: (910*910*0.00401)/2 = 1660.3405 J (energy)
To have the same energy an subsonic bullet will have a energy of X:
(340*340*X)/2 = 1660.3405
equals to:
X = (2*1660.3405)/(340*340) = 0.02872KG
X = 28.72 gm
So the bullet needs to have 7 times the mass
If the bullet is also 5.56 mm of radios then it will have to have 7 times the length of the standard 5.56 bullet to have the same energy.
This is impracticable it would not be a bullet, it would be an arrow.
so the bigger the caliber is, less long it needs to be to have the same energy.
thats why the best (standard rounds) calibers to be subbed are 9mm
An example of this is the 9x39mm SP-6 that has a mass of 16 gramms (4 times the 5.56mm)
The best (know by me) example is the 12.7mm special subsonic(VSSK) with 76 gram that travels at 290m/s. this bulet will diliver an energy of 3195.8 J (2 times the energy of an 5.56)
I hope this helps
[Updated on: Sun, 16 December 2007 07:17] by Moderator Report message to a moderator
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Sergeant
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| Re: Real life Weapon Questions[message #167742]
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Sun, 16 December 2007 10:35
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| afp |
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Messages:75
Registered:November 2007 |
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"I'm still confused something about the whole calibre issue. Generally it is said the large the calibre the more powerful the shot. So why is a 9mm generally weaker then lets say a 5.56mm?"
An image worth a thousand words  :
1. 7.62
2. 5.56
3. 9 mm
The images speak themselves, as you can see the 9 mm is small, you can cary a lot, the bullet shape itself does not suggest good piercing capability (in fact none, any body armor resist to it) - used for pistols and SMGs
5.56 is a fast bullet, a lot of gunpoder and the bullet not that big, high speed gives it good piercing capabilities - used by rifles and machine guns
7.62 is a big bullet, makes awfull wounds, similar armor piercing to 5.56 - used by rifles and machine guns
Of course, there are many types of each one.
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Corporal
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| Re: Real life Weapon Questions[message #189189]
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Fri, 20 June 2008 06:22
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| Skimmer |
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Messages:3
Registered:May 2008
Location: Middle of Nowhere, Oz |
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Arguably, the stun grenades could be a concussion effect, as opposed to a frag effect. Not literally dragging the air out of your lungs, but disorienting you, slamming you around etc. Imagine being punched hard, that's the concussion. Now imagine being stabbed instead, that's a frag grenade. Both can kill in reality (none of this -1) if they're close enough. Another option would be the 'sting' grenade (Just read about this in wikipedia), which basically shoots dozens of miniature rubber balls.
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Civilian
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| Re: Real life Weapon Questions[message #190673]
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Mon, 14 July 2008 00:39
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| Relentless707 |
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Messages:41
Registered:July 2008
Location: Leeds UK |
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Something else also in regards to a Bullet variation is the method it travels - the best description being like a corkscrew while it travels in the Air - contrary to normal idea of a bullet travelling in a single straight line akin to a Railgun all the while the bullethead remains at the front.
- So while the bullet is travelling in the Air the variations on it hitting a person are endless, because when it contacts the body the bullet could, if high enough Velocity just pass through the person or in other cases such as the 5.56 - the bullet can enter a person's shoulder and exit their hip due to the bullet being deflected inside the body causing severe wound trauma and the decrease in velocity from it impacting a person's flesh/body armour etc.
Although there are other bullet variations on Calibres that utilise a '' tumbling '' effect, creating devastating wounds on a target, this was more commonly used on .50 Calibre Machineguns in WW2 for example in Anti Aircraft roles as the .50 Calibre wouldn't just penetrate the metal armour, but it would tear a large hole through it so the effects on a human being don't really need a graphic description.
Hope this info helps.
Edit : Also the larger the Calibre the more power relates to the design of weaponry - the barrels being Rifled and this also causes the '' corkscrew '' effect as described above.
And, my educated guess from how/what AET ammo is from having a glance on the net etc is the Bullet design being similar to a Hollowpoint or Glaser but still has the armour piercing tip to penetrate body armour - but upon contact the inside of the bullet head shatters or '' squashes '' pushing out metal fragments, like a hollowpoint bullet '' mushrooming '' on contact, the AET would penetrate the armour, decrease in velocity, when entering the softer tissue of the human body the fragments would go outward. Again thats just my educated guess from the snippets I have read but I maybe entirely wrong.
[Updated on: Mon, 14 July 2008 00:46] by Moderator Report message to a moderator
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Corporal
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| Re: Real life Weapon Questions[message #191354]
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Mon, 21 July 2008 10:06
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| Starwalker |
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Messages:758
Registered:October 2005
Location: Hannover, Germany |
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We use the AET moniker for bullets that can have both AP and HP effects due to their construction, be that the special shape of THV or CIB/SIB ammo, or the special construction of the standard ammo in 5.7x28mm (aluminum body with steel tip, in a steel jacket).
Both bullets, when hitting something hard, transfer their energy mostly over their point.
When hitting a soft target, THV's point penetrates easily and the bullet transfers energy over the outer rim, like a semi-wadcutter. The 5.7x28mm begins to tumble inside a soft target, it's lightweight tail wagging around the far forward center-of-mass.
Both need quite high speed to achieve the desired effect.
This has been discussed at length in other threads already...
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| Re: Real life Weapon Questions[message #193809]
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Thu, 14 August 2008 02:39
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| Gunsgg |
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Messages:57
Registered:September 2004 |
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Two things are important for a killing shot, and these two kind of fluctuate in importance depending on the particular situation.
1) Mass times velocity. This tells you how much energy you are putting on target.
I'm going to give away my age here, but as a gunsmith I learned to think of kinetic energy in foot-pounds.
A large slow calibre has certain advantages over a small fast calibre because of
2) energy expended on target.
Meaning that a light fast calibre (5.56 is the same as the old .223) may carry 600 ft/lbs of energy to the target, pierce one side of the target and exit the other, expending 200 ft/lbs and retain 400 ft/lbs to waste it in the backstop----a wall or the ground.
A heavy calibre, such as the .45 ACP might strike the target with 600 ft/lbs of energy and stop....this means that ALL 600 ft/lbs were expended on target! A forty five striking a man will do terrible damage.
Lighter calibre weapons when used for hunting are usually equipped with hollow points. The nose of the bullet expands on contact, preventing overpenetration and allowing the bullet to expend all of it's energy.
Hollow points are illegal to use in warfare, so military rounds are designed with full metal jackets to keep them from expanding. A full metal jacket makes a round less deadly, not more so, except when the target is equipped with body armor.
The 5.56mm round was designed to circumvent this law, by designing the bullet with a boat tail. This causes the bullet to tumble upon impact, slowing it and allowing it to expend it's energy.
At close range, a thru round is not desirable on an attacker, as he may not go down.
[Updated on: Thu, 14 August 2008 02:46] by Moderator Report message to a moderator
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Corporal
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| Re: Real life Weapon Questions[message #194346]
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Mon, 18 August 2008 17:29
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| DNA from the Lowlands |
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Messages:337
Registered:July 2003 |
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Mmmh. the shot-soldier is in a bad position, moving more soldiers to that position seems like holding out a sign.
On the other hand what would shoot at medical personel ?
- VSS Vintorez, that would be the guns internal mechanism, still rather loud up close.
- AS Val? Microphone, bit further away ?
"With the advent of modern hostage rescue tactics in the 1970s and 1980s, the military and police agencies began to look for ways to minimize overpenetration risks. One widely-accepted solution was the frangible round, also known as the AET (Advanced Energy Transfer) round.
Frangible rounds are available in a wide array of pistol calibers, but due to the inherently high velocities of rifle rounds, frangible ammunition is much less effective in rifles. It is only produced in 5.56mm NATO and 7.62mm NATO, and its performance in actual combat is dubious. There are two frangible rounds that have been approved for training purposes only. One is a 9mm, and the other a 5.56. Approval for operational use will depend on the special mission requirements (the military necessity) for the round.
Frangible bullets are not made from a lead projectile covered with a copper jacket, but are composites of hybrid materials either pressed together at high pressure or glued together with adhesives. Frangible bullets are designed to break up into smaller pieces upon contact with harder objects or surfaces. The polymer-compound round produces no splashback and vastly decreased ricochets.
Frangible bullets will break up into small, less harmful, pieces upon contact with anything harder than they are. This maximizes the round's transfer of energy to the object and minimizes the chances that pieces of the bullet will exit the object at dangerous velocities. Each of the small fragments quickly loses any energy and therefore pose very little danger to any secondary targets. This means that full-power frangible bullets can be shot at target all the way up to muzzle contact without any worries that the bullet or case will ricochet and potentially hurt either the shooter or others." -source
The part where it said, "will break up into small, less harmful, pieces upon contact with anything harder than they are", to me that reads as if it wouldn't penetrate a vest.
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Master Sergeant
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