bradley aa version (w
Patrick Eves
From Patrick Eves <patric...@canrem.com>
GE> Problem with 30mm weapon use is there is no AP round in service
GE>- the A-10 and Apache AH-64 helicoter use a dual purpose 30mm round
GE>that is slow and probably won't defeat the future threat land combat
Someone will probably have already pointed this out by the time my message
makes the rounds, but I thought I should mention to Gallaghe that the
A-10 and the AH-64 have different types of 30mm cannon. Actually, the only
similarity is the caliber.
The GAU-8 Avenger used on the A-10 uses a special 30mm DU penetrator, on top of
a relatively enormous (roughly the size of a milk bottle) cartridge. The
A-10 is the only platform to carry the Avenger cannon.
The 30mm Hughes chain gun carried by the Apache uses the NATO standard 30mm
round, a smaller round used mostly by the British, called by them the 30mm
ADEN, I believe. British Harriers carry 30mm cannon chambered for this round,
and the Scimitar light tank uses the same round in its 30mm cannon. Going way
back, I think the first use was in the Fox armoured car, but I'm not sure.
---
~ DeLuxe} 1.25 #12341 ~ CLOSE COVER BEFORE STRIKING
--
Canada Remote Systems - Toronto, Ontario
World's Largest PCBOARD System - 416-629-7000/629-7044
Edward J. Rudnicki
From "Edward J. Rudnicki" (FSAC-SID) <erud...@pica.army.mil>
Patrick Eves writes:
#From Patrick Eves <patric...@canrem.com>
#
#
#GE> Problem with 30mm weapon use is there is no AP round in service
#GE>- the A-10 and Apache AH-64 helicoter use a dual purpose 30mm round
#GE>that is slow and probably won't defeat the future threat land combat
#
#Someone will probably have already pointed this out by the time my message
#makes the rounds, but I thought I should mention to Gallaghe that the
#A-10 and the AH-64 have different types of 30mm cannon. Actually, the only
#similarity is the caliber.
#
#The GAU-8 Avenger used on the A-10 uses a special 30mm DU penetrator, on top of
#a relatively enormous (roughly the size of a milk bottle) cartridge. The
#A-10 is the only platform to carry the Avenger cannon.
#
#The 30mm Hughes chain gun carried by the Apache uses the NATO standard 30mm
#round, a smaller round used mostly by the British, called by them the 30mm
#ADEN, I believe. British Harriers carry 30mm cannon chambered for this round,
#and the Scimitar light tank uses the same round in its 30mm cannon. Going way
#back, I think the first use was in the Fox armoured car, but I'm not sure.
You were doing fine until you mentioned the Scimitar and Fox :)
The GAU-8 uses a large bottlenecked 173mm long cartridge case. As used in
the A-10, three natures of ammunition are available: full-bore AP with
DU core, HE (these may be API and HEI; I don't remember), and TP.
When used in the Goalkeeper CIWS, the GAU-8 fires a tungsten penetrator
MPDS ("missile piercing discarding sabot" - I didn't make that up) round.
The 30mm Chain Gun used in the AH-64 uses ammunition based on the Aden/DEFA
family. This uses a very short cylindrical case. The service round used
with the Chain Gun is HEDP - High Explosive Dual Purpose, with a fluted
cone copper SC liner and a prefragmented steel body.
The Scimitar and Fox use the 30mm Rarden gun, whose ammunition is based
on an Oerlikon 30mm round (KCB?) more powerful than the Aden/DEFA but
not quite as good as the 30x173 of the GAU-8.
Ed Rudnicki erud...@pica.army.mil All disclaimers apply
"War must be looked upon as a business, and subject, like any other business,
to business principles. War is the business of destruction of life and
property of an enemy.....The most deadly and destructive implements of war
are the most humane, and the producers of them may justly be looked upon as
humanitarians." ----- Hudson Maxim (the other Maxim)
Dave Heisler
From Dave Heisler <dhei...@fieldofdreams.npirs.purdue.edu>
I had this idea the other day, lets say you have an airport
or base that comes under sporadic sniper fire. How do you
locate the sniper?
I envisioned this: hundreds of self powered radio linked
microphones scattered about the ground. A control unit that
knows the position of all of them (relative to control unit
or maybe use gps) and can calculate direction of sound orgin
based on the timing of the received sound pulse as radioed by
the microphones. (thinking about it maybe you could get by with
2 or 3 sensor microphones)
1) Combine direction of orgin with an overhead satelite view.
2) Programmable microphone filter/amplifyer for detecting other
things like tanks, airplanes, etc.
comments?
dave
Patrick Eves
From Patrick Eves <patric...@canrem.com>
EJ>You were doing fine until you mentioned the Scimitar and Fox :)
EJ>The Scimitar and Fox use the 30mm Rarden gun, whose ammunition is based
EJ>on an Oerlikon 30mm round (KCB?) more powerful than the Aden/DEFA but
EJ>not quite as good as the 30x173 of the GAU-8.
Thanks for the correction, Ed. If I'm going to be splitting 30mm hairs with
another fellow, I'd better expect some backblast. ;)
Dan Sorenson
From Dan Sorenson <vik...@iastate.edu>
Dave Heisler <dhei...@fieldofdreams.npirs.purdue.edu> writes:
>I had this idea the other day, lets say you have an airport
>or base that comes under sporadic sniper fire. How do you
>locate the sniper?
>I envisioned this: hundreds of self powered radio linked
>microphones scattered about the ground. A control unit that
>knows the position of all of them (relative to control unit
>or maybe use gps) and can calculate direction of sound orgin
>based on the timing of the received sound pulse as radioed by
>the microphones. (thinking about it maybe you could get by with
>2 or 3 sensor microphones)
It sounds to me like you just re-invented the passive
sonobuoy and placed it on land. It could certainly work, and
I doubt you would need more than a dozen along a 1-mile
perimeter to work out just where your sniper is. Had this
been used for perimeter security before?
What other methods might be used? I doubt a bullet
will heat up the surrounding air enough to leave a thermal
signature, so IR goggles are out, but they might be of use
in glassing the area for warm bodies.
< Dan Sorenson, DoD #1066 z1...@exnet.iastate.edu vik...@iastate.edu >
< ISU only censors what I read, not what I say. Don't blame them. >
< "Are you *SURE* he's worth a Harley-Davidson?" -- my grandmother >
< to my girlfriend, about me. "I'd better not say" -- my girlfriend >
dave pierson
From dave pierson <pie...@empror.enet.dec.com>
In article <C02w5...@law7.DaytonOH.NCR.COM>, Dave Heisler
<dhei...@fieldofdreams.npirs.purdue.edu> writes, in part:
>I had this idea the other day, lets say you have an airport
>or base that comes under sporadic sniper fire. How do you
>locate the sniper?
>
>I envisioned this: hundreds of self powered radio linked
>microphones scattered about the ground. A control unit that
>knows the position of all of them (relative to control unit
>or maybe use gps) and can calculate direction of sound orgin
>based on the timing of the received sound pulse as radioed by
>the microphones. (thinking about it maybe you could get by with
>2 or 3 sensor microphones)
Hundreds is probably overkill. Such schemes, with lesser numbers of
observers, date at least to WWI. (see the recent postings on the
Paris Gun...). A relatively small number of points and soem analysis
(cheaper by the day) will locate the source. (Of course, if I was the
source, I'd MOVE. (one school of sniperthought says stay and hide well,
but against that sort of counter, a rapid move sounds a lot better...))
I don't know if acoustic and flash ranging, for counterbattery work
are still in use, in this day of radar. Both are passive, so maybe, in
a high ecm, high "HARM" environment.
thanks
dave pierson |the facts, as accurately as i can manage,
Digital Equipment Corporation |the opinions, my own.
pie...@msd26.enet.dec.com | I am the NRA.
"He has read everything, and, to his credit, written nothing." A J Raffles
Daniel Kuan Li Oi
From Daniel Kuan Li Oi <d...@tartarus.uwa.edu.au>
Dave Heisler <dhei...@fieldofdreams.npirs.purdue.edu> writes:
>From Dave Heisler <dhei...@fieldofdreams.npirs.purdue.edu>
>comments?
>dave
I know that this has been done for mortar location but why muck
around with sound filtering gear and all that when you could use radar
combined with doppler filtering to directly track incoming bullets and
trace the trajectory to the sniper.
With sound location, the technique might be defeated with use of
sound suppression gear on the rifle. Although the bullets might be still
supersonic, the initial crack of firing would be reduced so that
pinpointing the source of the bullet might be too hard.
Anyother comments anyone?
Daniel Oi
University of Western Australia
Disclaimer:Hey, I'm only a first year (not for long). What's your
excuse?
Jason Scott Cash
From ca...@calvin.ee.udel.edu (Jason Scott Cash)
>The 30mm Chain Gun used in the AH-64 uses ammunition based on the Aden/DEFA
>family. This uses a very short cylindrical case. The service round used
>with the Chain Gun is HEDP - High Explosive Dual Purpose, with a fluted
>cone copper SC liner and a prefragmented steel body.
>
>The Scimitar and Fox use the 30mm Rarden gun, whose ammunition is based
>on an Oerlikon 30mm round (KCB?) more powerful than the Aden/DEFA but
>not quite as good as the 30x173 of the GAU-8.
>
>Ed Rudnicki erud...@pica.army.mil All disclaimers apply
The Warrior also uses the RARDEN 30mm, as well as a few FV432's that have
the Scimitar's turret fitted on top. Speaking of the Warrior, I read an
article in JDW about a year ago that claimed that the Brits were
ordering some Warriors with MILANs. A later article had a picture included
Are they going ahead with this, or is this a budget casualty?
If they are going ahead with this, does anyone know how these will be
deployed? Will they replace the FV432's with MILANs as the mechanized
battalions AT vehicles, as the article contends? This seems rather silly
to me. Why not have one Warrior per platoon fitted with MILANs? They
have relatively few Warriors, why waste them as makehshift AT vehicles?
Jason Cash
ca...@udel.edu
Keith Lewis
From le...@aera8700.mitre.org (Keith Lewis)
In article <C02w5...@law7.DaytonOH.NCR.COM>, Dave Heisler <dhei...@fieldofdreams.npirs.purdue.edu> writes:
>I had this idea the other day, lets say you have an airport
>or base that comes under sporadic sniper fire. How do you
>locate the sniper?
>
>I envisioned this: hundreds of self powered radio linked
>microphones scattered about the ground. A control unit that
>knows the position of all of them (relative to control unit
>or maybe use gps) and can calculate direction of sound orgin
>based on the timing of the received sound pulse as radioed by
>the microphones. (thinking about it maybe you could get by with
>2 or 3 sensor microphones)
Three or four mics, if you're dealing with a relatively unobstructed space
with a uniform temperature.
>1) Combine direction of orgin with an overhead satelite view.
Your basic microphone doesn't sense direction, just time. Two together give
you a hyperbola via constant time (distance) difference. If your mics are
relatively close together, you can approximate it with two bearings.
>2) Programmable microphone filter/amplifyer for detecting other
> things like tanks, airplanes, etc.
Yeah, a filter would be good. Especially if you need to handle supersonic
bullets (are any/all bullets supersonic?). We wouldn't want/need the device
to tell us where the bullet *hit*. :^)
Tanks are harder. Sure, you can isolate the sound of the tank engine at
each microphone, but since it's a periodic function, there are multiple time
(distance) differences that will match them up. To determine which is
correct, you need to wait for it to rev its engine, or (better yet)
backfire. You can solve this problem by installing your microphones in
pairs. The distance between a pair of mics should be less than half the
smallest wavelength you want to measure (that would be about a meter for a
V-8 engine running at 2000 rpm). That way you can just match up the nearest
peaks.
Airplanes are tougher still, because you get a serious Doppler effect that
screws with your filtering and matching. With pairs of mics near each
other, you might be able to get bearings, but by the time you get the info,
the aircraft could have moved. It's best to use radar.
Keith Lewis kle...@mitre.org "Mr. Cheap"
The above may not (yet) represent the opinions of my employer.
Brian Douglass
From Brian Douglass <anasaz!bri...@anasazi.com>
In article <C0CC6...@law7.DaytonOH.NCR.COM> le...@aera8700.mitre.org (Keith Lewis) writes:
>
>From le...@aera8700.mitre.org (Keith Lewis)
>
>In article <C02w5...@law7.DaytonOH.NCR.COM>, Dave Heisler <dhei...@fieldofdreams.npirs.purdue.edu> writes:
>>I had this idea the other day, lets say you have an airport
>>or base that comes under sporadic sniper fire. How do you
>>locate the sniper?
[deleted stuff]
>Airplanes are tougher still, because you get a serious Doppler effect that
>screws with your filtering and matching. With pairs of mics near each
>other, you might be able to get bearings, but by the time you get the info,
>the aircraft could have moved. It's best to use radar.
Isn't such an acoustic system similar to the "Big Ears" system described in
the book/movie FireFox? Was there ever such an acoustical tracking system
in the USSR?
Edward V. Wright
From "Edward V. Wright" <ewr...@convex.com>
Dave Heisler <dhei...@fieldofdreams.npirs.purdue.edu> writes:
>I had this idea the other day, lets say you have an airport
>or base that comes under sporadic sniper fire. How do you
>locate the sniper?
>I envisioned this: hundreds of self powered radio linked
>microphones scattered about the ground.
If the existance of the device becomes know, it would be
vulnerable to counter-countermeasures. Simply put, the
sniper could wait until a plane was taking off and use
the noise to mask the shot.
Ethan L Mckinney
From Ethan L Mckinney <mcki...@athena.mit.edu>
1) The US deployed large numbers of passive listening devices in Vietnam -- That
didn't seem to solve the sniper problem. Try working out the math for how many
you need to cover an area reliably and you'll get a feeling for the problem.
Data processing would also be ... impressive.
2) Yes, most bullets are supersonic, which is why they make scary "cracking"
noises when they go overhead. One of the functions of a silencer is to
decelerate the bullet below Mach 1 (on rifles, that is). Most pistol rounds are
subsonic, making them much easier to silence (rifle silencers suck).
3) Actually, some Germans are working on systems using passive listeners for CFE
verification. Turns out sonic sensors work very well for this, and you can tell
vehicle types apart, because tanks and trucks vibrate differently, and you can
even tell different tank models and their speeds apart because the frequencies
are different. Aircraft can be distinguished by engine type and number. Ranges
are somewhat short, though.
E
Nick Pomponio
From n...@prism.gatech.edu (Nick Pomponio)
In article <C02w5...@law7.DaytonOH.NCR.COM>, Dave Heisler <dhei...@fieldofdreams.npirs.purdue.edu> writes:
>I had this idea the other day, lets say you have an airport
>or base that comes under sporadic sniper fire. How do you
>locate the sniper?
>
>I envisioned this: hundreds of self powered radio linked
>microphones scattered about the ground. A control unit that
>knows the position of all of them (relative to control unit
>or maybe use gps) and can calculate direction of sound orgin
>based on the timing of the received sound pulse as radioed by
>the microphones. (thinking about it maybe you could get by with
>2 or 3 sensor microphones)
Passive sensors are probably a good choice for detecting non-repetitive
events such as sporadic gunfire. Your approach seems possible. Here are
a couple of design considerations I thought of:
1) Ambient noise - A setting such as an airport would probably have a
wide spectrum of high-level ambient noise, from the high-pitched whine
of jet engines to the low frequency rumble of the aircraft during take-off.
The filters for isolating gunshots would have to be pretty sophisticated
(probably linear-phase, also, in order to retain the pulse shape for
accurate Time-Of-Arrival measurement).
2) In order to compute unambiguous range and angle to the sniper, the time
between shots would probably have to be greater than the worst case
difference in propagation delay between any two sensors. This may render
the scheme uneffective for machine-gun fire or separated synchronized firings.
--
POMPONIO,NICHOLAS A
Georgia Institute of Technology, Atlanta Georgia, 30332
uucp: ...!{decvax,hplabs,ncar,purdue,rutgers}!gatech!prism!np4
Internet: n...@prism.gatech.edu
cval...@vmsb.is.csupomona.edu
From cval...@vmsb.is.csupomona.edu
The Brits make a device that shows what direction a bullet came from. It
can be mounted on a vehicle or manpacked. I think it's some sort of radar
though I'm not really sure on that point. Anyways, you have a readout that
shows what direction the bullet came from. I'll have to look up the rest of
the details in my book at home.
--
--------------------------------------------------------------------------------
Daemon E. Hobbs, C/LtCol, AFROTC
Senior, (Spatial Information Systems)
Cal Poly, Pomona
**Commander**
602D Air Force ROTC Cadet Squadron (ATC)
Harvey Mudd College, Claremont, CA 91711
"I've filled out DEHR Form 1-1, Opinion Request, and therefore have only my
own opinion. For those who have a problem with that, fill out (in
triplicate) DEHR Form 1-2, Need A Life Recquisition Form."
--------------------------------------------------------------------------------
Tarl Neustaedter
From Tarl Neustaedter <ta...@lectroid.sw.stratus.com>
In article <C0E5p...@law7.DaytonOH.NCR.COM>, Ethan L Mckinney <mcki...@athena.mit.edu> writes:
> 2) Yes, most bullets are supersonic, which is why they make scary "cracking"
> noises when they go overhead. One of the functions of a silencer is to
> decelerate the bullet below Mach 1 (on rifles, that is). Most pistol rounds are
> subsonic, making them much easier to silence (rifle silencers suck).
Minor correction. A silencer muzzles (sic) the blast from the propellant.
It does *NOT* decelerate a bullet to subsonic speeds. A silencer will slightly
reduce muzzle velocity of bullets, but not by a factor of 3 (mach 3 to mach 1).
A silencer for sub-sonic ammo (e.g., .45 ACP) can be VERY effective, and indeed
the noise of the bullets hitting the target may be louder and/or more
noticeable than the sound the the firearm. The particular example I ran
into was a silenced UZI, shooting at a (defunct) car. The bullets splatting
into the side of the car were louder than the sound of the UZI action cycling,
even though I was closer to the UZI than the car.
A silencer for supersonic ammo (any rifle ammo) is much less effective. It
is useful in that hearing protection probably isn't required to fire the
rifle, but it doesn't hide the fact that someone just fired a shot. These
silencers also probably don't last as long; one guy with an M-16 emptied
a 30-round magazine and the last several shots were noticeably louder than
the first few. I suspect the various diaphragms had ruptured or torn.
--
Tarl Neustaedter ta...@sw.stratus.com
Marlboro, Mass. Stratus Computer
Disclaimer: My employer is not responsible for my opinions.
Jim Heath
From Jim Heath <jhe...@fieldofdreams.npirs.purdue.edu>
>From article <C0E5p...@law7.DaytonOH.NCR.COM>, by Ethan L Mckinney <mcki...@athena.mit.edu>:
>
> From Ethan L Mckinney <mcki...@athena.mit.edu>
>
> 1) The US deployed large numbers of passive listening devices in Vietnam -- That
> didn't seem to solve the sniper problem. Try working out the math for how many
> you need to cover an area reliably and you'll get a feeling for the problem.
> Data processing would also be ... impressive.
The listening devices in Nam were for other purposes, like are there
people around where they are placed (or am I mistaken?).
I suspect that a computer system _might_ be fast enough to handle the
problem, but I'm a programmer, not a mathamatician ;-{).
> 2) Yes, most bullets are supersonic, which is why they make scary "cracking"
> noises when they go overhead. One of the functions of a silencer is to
> decelerate the bullet below Mach 1 (on rifles, that is). Most pistol rounds are
> subsonic, making them much easier to silence (rifle silencers suck).
It seems to me that subsonic rifle shots would negate the idea of the
sniper, or at least interfer with his/her mission - to kill at fairly long
range. The slower the bullet, the longer the target has to move out of
its path. This isn't much of a problem at close range, but can develop
into one at longer ranges. 'Course it now occurs to me to wonder how well
this system would work on a sniper who was the better part of a mile away.
--
"Land of song, said the warrior bard, Jim Heath
Though all the world betrays thee.
One sword, at least, thy rights shall guard, (The Minstrel Boy)
One faithful harp will praise thee." (Thomas Moore)
Gary Coffman
From Gary Coffman <emory!ke4zv!ga...@gatech.edu>
In article <C0E5p...@law7.DaytonOH.NCR.COM> Ethan L Mckinney <mcki...@athena.mit.edu> writes:
>2) Yes, most bullets are supersonic, which is why they make scary "cracking"
>noises when they go overhead. One of the functions of a silencer is to
>decelerate the bullet below Mach 1 (on rifles, that is). Most pistol rounds are
>subsonic, making them much easier to silence (rifle silencers suck).
Silencers do not slow bullets below the speed of sound. They only
muffle the noise of the discharge. If the round is supersonic, it
still "cracks", but the muffling of the discharge makes direction
finding more difficult because you now have a line source instead
of a point source for the sound. Most .45ACP rounds are subsonic,
certainly in military loadings, but most 9mm loadings are supersonic
except for 147 gr loadings. Even the lowly .22LR is supersonic.
Gary
--
Gary Coffman KE4ZV | You make it, | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems | we break it. | uunet!rsiatl!ke4zv!gary
534 Shannon Way | Guaranteed! | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244 | | emory!ke4zv!ga...@gatech.edu
Paul Tomblin
From PTom...@gvc.com (Paul Tomblin)
Dan Sorenson <vik...@iastate.edu> writes:
>Dave Heisler <dhei...@fieldofdreams.npirs.purdue.edu> writes:
>>I had this idea the other day, lets say you have an airport
>>or base that comes under sporadic sniper fire. How do you
>>locate the sniper?
>>I envisioned this: hundreds of self powered radio linked
>>microphones scattered about the ground. A control unit that
>>knows the position of all of them (relative to control unit
> It sounds to me like you just re-invented the passive
>sonobuoy and placed it on land. It could certainly work, and
Funny - what goes around comes around. In the book ``Vimy'', buy Pierre
Berton, he talks about using sound ranging to do counter-battery artillery
in WWI, especially in the prelude to Vimy.
Of course, with computers and such, it would be a lot easier to trace
smaller things (such as bullets) more precisely, and faster.
(Of course, you get one or two people firing on full auto, and I think you'd
have an insurmountable problem)
Isn't the phalynx capable of correcting it's own line of fire by comparing
the radar image of the outgoing bullets with where it _wants_ them to go?
--
Paul Tomblin, speaking from but not for GeoVision Systems Inc.
"He who hasn't hacked assembly language as a youth has no
heart. He who does so as an adult has no brain."
- John Moore (jo...@asuvax.eas.asu.edu) on rec.humor.funny
Dan Simkins
From da...@bigbird.llnl.gov (Dan Simkins)
I find your contention that rifle silencers work by decelerating the bullet to subsonic speeds
very difficult to believe. If you are sure you are right, I would appreciate references showing
this to be the case.
My arguments against:
1) The most significant factor in the report of a firearm comes from supersonic gases escaping at
the muzzle, not the shock from the bullet. The 45 ACP is always subsonic, yet produces alot of
noise. If your contention was correct, there would be no need for a silencer on the 45 ACP.
2) In the case of a 223 Rem, it has a muzzle velocity of about 3200 fps generated in a 24" barrel.
I have never seen a rifle silencer in real life but the pictures I have seen indicate they are
about 12" long. So, in 24" a large pressure pulse accelerates the bullet to mach 3, and your
silencer model decelerates it to less than mach 1 in 12", question where does that force come
from? Friction? A very simplistic application of the impulse momentum theorem indicates that
the decelerating force must be about 1.63 times the net force that accelerated the bullet.
3) A subsonic rifle bullet would seem to defeat the operation. The trajectory would be radically
different. In fact, such a rifle bullet would have a trajectory that is more like a .22 long rifle
than a high-power rifle. The energy of a bullet is a function of the square of the velocity, hence
a subsonic is very low. Assuming a 55 gr. bullet at 3200 f/s at the muzzle gives about 1250 lb-ft
of energy, the same bullet at 1000 f/s ( speed of sound about 1130 f/s) gives 122 lb-ft of energy,
which I recall to be about that of a 22 long rifle. These factors seem to me to make a subsonic
rifle useless as a sniper rifle.
The speed of sound came from the CRC handbook. The other numbers are easily found in any Remington
catalog. If anyone is interested, I will be happy to provide the missing details from the above
calculations and/or contentions.
I contend that a silencer is nothing but a baffle that decelerates the burning gases to subsonic
levels, while hardly, if at all, affecting the bullet.
If there is anyone who REALLY knows how a silencer works, please email me.
lio...@maple.circa.ufl.edu
From lio...@maple.circa.ufl.edu
In article <C0G1...@law7.DaytonOH.NCR.COM>, ta...@lectroid.sw.stratus.com (Tarl Neustaedter) writes:
>A silencer for supersonic ammo (any rifle ammo) is much less effective. It
>is useful in that hearing protection probably isn't required to fire the
>rifle, but it doesn't hide the fact that someone just fired a shot. These
>silencers also probably don't last as long; one guy with an M-16 emptied
>a 30-round magazine and the last several shots were noticeably louder than
>the first few. I suspect the various diaphragms had ruptured or torn.
>--
> Tarl Neustaedter ta...@sw.stratus.com
> Marlboro, Mass. Stratus Computer
>Disclaimer: My employer is not responsible for my opinions.
Hmmm...McMillan makes a few sniper rifles in .300WM that are fully suppressed
with full length integral barrel suppressors. These weapons have been known
to kill out to 300 yards and are completely quiet. According to one SEAL
who used one in Desert Storm:
"It takes a while getting used to the sound of a bullet tearing through
a human body. And you can hear it all too well with these weapons."
[mod note -- by .300WM are you refering to a .300 Winchester Magnum or .300
Weatherby Magnum?
Steve]
Brian
Greg Finn
From Greg Finn <fi...@isi.edu>
In article <C0utI...@law7.DaytonOH.NCR.COM> lio...@maple.circa.ufl.edu writes:
>Hmmm...McMillan makes a few sniper rifles in .300WM that are fully suppressed
>with full length integral barrel suppressors. These weapons have been known
>to kill out to 300 yards and are completely quiet. According to one SEAL
>who used one in Desert Storm:
I concur with the comments made earlier. This sounds wrong.
Consult Duncan Long's book on combat ammunition for a short discussion
of why this is not likely. The supersonic crack is very loud. On the
other hand, if the suppressor lowers the velocity to subsonic, why use
a .300 Weatherby?
--
Gregory Finn (310) 822-1511
Information Sciences Institute, Marina Del Rey, CA 90292
Adrian Hurt
From Adrian Hurt <adr...@cee.heriot-watt.ac.uk>
In article <C0syv...@law7.DaytonOH.NCR.COM> da...@bigbird.llnl.gov (Dan Simkins) writes:
>
>I find your contention that rifle silencers work by decelerating the bullet
>to subsonic speeds very difficult to believe. If you are sure you are right,
>I would appreciate references showing this to be the case.
I don't know how accurate it is, but there's "The Armory" by Kevin Dockery, a
book containing a little information on a lot of guns and ammunitions and
intended mainly as a role-playing game sourcebook. Here is what it says
about the Sterling L34A1, a silenced version of the Sterling SMG.
"This weapon consists of a standard Sterling L2A3 with a built-on (permanently
attached) suppressor. Due to the suppressor's design slowing down the velocity
of the bullet, the L34A1 does not have the range of the standard Sterling but
can fire quietly with the standard ammunition. It is not recommended to fire
the weapon on full automatic for any length of time as the suppressor quickly
heats up and clogs, cutting down on its sound suppression."
The book gives the muzzle velocity of the standard Sterling as 1280 feet/s,
and the muzzle velocity of the L34A1 as 1010 feet/s. The MP5SD3, a silenced
version of the Heckler & Koch MP5 SMG, has its muzzle velocity listed as
935 feet/s as opposed to the 1312 feet/s of the unsilenced MP5A2, and the
1230 feet/s of the short MP5K.
--
"Keyboard? How quaint!" - M. Scott
Adrian Hurt | JANET: adr...@uk.ac.hw.cee
UUCP: ..!uknet!cee.hw.ac.uk!adrian | ARPA: adr...@cee.hw.ac.uk
Blair Haworth
From Blair Haworth <Blair....@lambada.oit.unc.edu>
In article <C0utI...@law7.DaytonOH.NCR.COM> lio...@maple.circa.ufl.edu writes:
>Hmmm...McMillan makes a few sniper rifles in .300WM that are fully suppressed
>with full length integral barrel suppressors. [...]
>[mod note -- by .300WM are you refering to a .300 Winchester Magnum or .300
>Weatherby Magnum?
>
>Steve]
That's Winchester. The Army also fooled around with the .338 WinMag and a
.308/.338 wildcat.
--
The opinions expressed are not necessarily those of the University of
North Carolina at Chapel Hill, the Campus Office for Information
Technology, or the Experimental Bulletin Board Service.
internet: laUNChpad.unc.edu or 152.2.22.80
Frank Crary
From fcr...@ucsu.Colorado.EDU (Frank Crary)
In article <C0syv...@law7.DaytonOH.NCR.COM> da...@bigbird.llnl.gov (Dan Simkins) writes:
>I find your contention that rifle silencers work by decelerating the bullet to subsonic speeds
>My arguments against:
>1) The most significant factor in the report of a firearm comes from supersonic gases escaping at
> the muzzle, not the shock from the bullet. The 45 ACP is always subsonic, yet produces alot of
> noise.
That's a pistol round. Your quite correct to say most of the report from
a _pistol_ is gas escaping the muzzel. However, the shockwave from a
supersonic rifle bullet is a large part of a rifle's report.
>2) In the case of a 223 Rem, it has a muzzle velocity of about 3200 fps generated in a 24" barrel.
I suspect many calibers couldn't be silenced effectively. I've never
heard of a silencer for an M-16, or anything else firing .223 Rem.
I _think_ silencers which slow the bullet to subsonic speeds are generally
for submachineguns and carbines whose bullets are normally only slightly
supersonic. Alternately, it might be possible to silence .223 Rem, if
a reduced powder load was used (of course, this probably wouldn't
cycle the action...)
>3) A subsonic rifle bullet would seem to defeat the operation. The trajectory would be radically
> different. In fact, such a rifle bullet would have a trajectory that is more like a .22 long rifle
> than a high-power rifle. The energy of a bullet is a function of the square of the velocity, hence
> a subsonic is very low.
I don't think anyone said a silencer didn't effect the ballistics...
If there wasn't a major price to pay for using a silencer, wouldn't
they be a common feature on military rifles? Also, I think a subsonic,
silenced rifle round would be more like a pistol round of the same
caliber, not a .22LR (I.e. .223Rem would be like .22LR, .308Win roughly
like 9mm/.357, .50BMG like .44) I think it's because of these
disadvantages, that military snipers rarely use silencers.
Frank Crary
CU Boulder
Dan Sorenson
From Dan Sorenson <vik...@iastate.edu>
fcr...@ucsu.Colorado.EDU (Frank Crary) writes:
>I suspect many calibers couldn't be silenced effectively. I've never
>heard of a silencer for an M-16, or anything else firing .223 Rem.
>I _think_ silencers which slow the bullet to subsonic speeds are generally
>for submachineguns and carbines whose bullets are normally only slightly
>supersonic. Alternately, it might be possible to silence .223 Rem, if
>a reduced powder load was used (of course, this probably wouldn't
>cycle the action...)
This was discussed on rec.guns a while back, and a FAQ is in the
works. Hopefully the moderator will cross-post when it is on-line. In
any event, the only .223 I've seen with silencers weren't particularly
silent, Sarah Connor in Terminator 2 notwithstanding.
[mod note -- sure, I'll post the rec.guns FAQ whenever I see it
Steve]
However, one selling point of the HAC-7, made by Holloway
Arms Corporation as a battle rifle (I hate to say 'salt weapon), was
an adjustable gas regulator. It was chambered in 7.62 NATO, and was
capable of being silenced. There were five positions on the gas
regulator, the first four being for heavy-to-light ammunition, and the
last being no gas at all. This last setting was to be used with
subsonic ammunition and silencer, and kept the bolt from opening at
all in order to reduce noise. Is this even made today? I read about
it at least five years ago.
I'd suggest that an M-16 could fire suppressed, but you would
need to adjust the gas regulator to cycle the action, or just cycle
it by hand after each shot.
Additionally, silencers work like glasspack mufflers on cars.
The silencer absorbs the heat and blast from the muzzle. It does not
slow the bullet. Those that might must be an integral part of the
barrel (holes drilled in it?) else your accurracy is killed along with
the sound. A supersonic bullet and a silencer are, at best, going to
silence the initial report, and is hence somewhat less than ideal.
< Dan Sorenson, DoD #1066 z1...@exnet.iastate.edu vik...@iastate.edu >
< ISU only censors what I read, not what I say. Don't blame them. >
< USENET: Post to exotic, distant machines. Meet exciting, >
< unusual people. And flame them. >
Jim Heath
From Jim Heath <jhe...@fieldofdreams.npirs.purdue.edu>
>From article <C15yL...@law7.DaytonOH.NCR.COM>, by Adrian Hurt <adr...@cee.heriot-watt.ac.uk>:
>
> From Adrian Hurt <adr...@cee.heriot-watt.ac.uk>
>
> In article <C0syv...@law7.DaytonOH.NCR.COM> da...@bigbird.llnl.gov (Dan Simkins) writes:
>>
>>I find your contention that rifle silencers work by decelerating the bullet
>>to subsonic speeds very difficult to believe. If you are sure you are right,
>>I would appreciate references showing this to be the case.
>
> I don't know how accurate it is, but there's "The Armory" by Kevin Dockery, a
> book containing a little information on a lot of guns and ammunitions and
> intended mainly as a role-playing game sourcebook. Here is what it says
> about the Sterling L34A1, a silenced version of the Sterling SMG.
>
Beg your pardon, but the Sterling is a machine _pistol_ (submachine gun),
not a rifle. I think silencers slow the bullet a bit, but won't make it
subsonic unless it nearly is to begin with. (subsonic < 1100 fps isn't
it?) The 9mm (?) the Sterling fires is barely supersonic. A rifle bullet
is usually around 3000 fps.
lio...@maple.circa.ufl.edu
From lio...@maple.circa.ufl.edu
The SEALs use handloaded rounds for long distance firing, and for short
range they use the suppressed weapons with a special Finnish subsonic
load. It might have been Norwegian loads.
>From the article I gathered that they use the subsonic ammunition for close
in work and the other stuff for long distance. The prefer .300WM I guess
because in general it is harder hitting, retains more energy, and also
flies flatter ( assuming supersonic travel ) compared to the .308.
The two exact accounts listed of the weapon use were two confirmed kills
of sentries situated on an oil platform, hit at night from a Zodiac
approx 300 yards away, using subsonic ammo. The other confirmed was
hitting a tank commander in the head as he peeked out of his hatch from
800 yards away, using supersonic ammo.
Brian
PS Some confusion may arise because McMillan makes both a suppressed and
non-suppressed version of the M89. The non-suppressed is available for
sale to public. About 2000 dollars.
Frank Crary
From fcr...@ucsu.Colorado.EDU (Frank Crary)
In article <C17vx...@law7.DaytonOH.NCR.COM> fcr...@ucsu.Colorado.EDU (Frank Crary) writes:
>I suspect many calibers couldn't be silenced effectively. I've never
>heard of a silencer for an M-16, or anything else firing .223 Rem.
After I posted this, someone pointed out, in e-mail, that there is
a silencer for the M-14 (.308 Win). It has no effect at all on the
supersonic shockwave/report of the bullet, but apparently this
doesn't matter for military purposes: Unlike the noise produced
at the muzzel, the shockwave doesn't give away the location of the
sniper (I assume because it isn't produced at the sniper's location,
but along the line of fire.) With such a silencer, people would know
there was a sniper _somewhare_, but they wouldn't know where, exactly,
he was.
Frank Crary
CU Boulder
Jordan K. Hubbard
From j...@whisker.lotus.ie (Jordan K. Hubbard)
As far as I know, no current suppressor technology exists that
actually slows supersonic rounds to the subsonic (even trying to do
such a thing strikes me as a highly dangerous proposition), you need
to load special ammunition that is already subsonic. All the
suppressor does is prevent rapid expansion of gases released at the
muzzle. It's also true that most automatic weapons release
substantial noise from the opening breach, which is why truly
"silenced" weapons lock the breach for every shot (you need to cycle
the action by hand).
I think trying to develop suppression technology for rifle rounds is
probably pointless for anything in the SMG / LMG range - the only
effective suppressors I've ever seen for such things being massive and
only usable from a tripod mounted weapon (sighting was also a serious
problem). I can't really imagine such a weapon being used in any
situation that a flash suppressed weapon (to prevent dust dispersion)
couldn't do equally well, assuming that the goal was to snipe at
relatively long range from a concealed location for an extended period
of time (without detection). The sonic crack is always going to point
you out eventually, however.
Jordan
--
Jordan Hubbard Lotus Development Ireland j...@whisker.lotus.ie
I DO NOT SPEAK FOR LOTUS - IT HAS PLENTY OF LAWYERS TO DO THAT FOR IT ALREADY