Newsgroups: rec.pyrotechnics
From: ahahma@utu.fi (Arno Hahma)
Subject: Re: Silencers
Date: Sun, 4 Dec 1994 12:56:03 GMT

>In article <3brta7$721@ixnews1.ix.netcom.com>,
>Gary Gerlach <ggerlach@ix.netcom.com> wrote:

>>In <GDS-2811941516470001@h-claudio.nr.infi.net> GDS@NR.INFI.NET 
>>(Somebody) writes: 


>>--Will the 2-liter bottle silencer work on a single-barrel 12-gauge 
>>shotgun? If not, can it be silenced by other means?

Probably not too much. Still, a shotgun can be silenced, very
effectively indeed.

>The answer to both questions is "NO WAY!"  Not remotely.  The gas load 
>from a shotgun is enormous. Any effective silencer for that amount of 

Not exactly true. The gas load depends on only the powder charge. A
typical shotgun shell contains less powder than a typical rifle
cartridge, so there is really no problem about the gas amount. The
problem is, that the pressures are low and the muzzle diameter is
large, so you have to have a large silencer to deal with those
(more port are into the silencer than out of the barrel).

>gas would be at least as big as that for a large automobile. Secondly, 
>the shot is super sonic, thereby generating a super sonic 'boom' or 
>shock wave that cannot be silenced (except in a vacuum).

Even if the supersonic noise is there, the overall noise
level drops significantly. Besides, for a silenced gun
you'll want to make subsonic ammo anyway, if you want the
gun to be really quiet.

>>even if it did work, the pattern would be so mangled that it wouldn't 
>>be effective over 10 feet.

>This is unlikely. Only the first few pellets would be significantly 
>deformed. The amount of shot in a 12 gauge shotgun is substantial. 

This is definitely not true. The pattern will actually get _much_
tighter and you will get extra range with a silenced shotgun.  The
spread of the pattern results from the hot gases passing the pellets at
the muzzle and that fast flowing gas generates forces to the pellets.
As these forces are directed more or less randomly, the pellets will
get more or less random directions.

The reason why a long barreled shotgun makes a better group is that the
gases cool down in the long barrel and there are less gases at the
muzzle and at a lower velocity. If we think about a silencer, it is far
more effective in bleeding off the gases from behind the shot than a
long barrel is. Therefore, a buckshot fired off a silenced shotgun is
like a SMG burst, the pellets go almost through the same hole at a long
distance. The noise is just a "puff" and the recoil is also reduced by
about 30..50 %.

ArNO
    2

From: John De Armond
Subject: Re: Full auto suppressors?
Organization: Dixie Communications Public Access

zo@maple.circa.ufl.edu writes:


#The questions I have now are:

#1.  Are there in fact suppressors now available that allow you to fire
#full auto ( Terminator 2, assassination sequence on Miles Dyson, Linda
#uses M16A2 full auto with laser sight and suppressor ).

Yes.  My friend the gunsmith where I moonlite has a MAC-10 in .380 with
a LARGE Sionics suppressor.  You can rest assured that this little
critter can quietly eat more ammo in a minute than I can reload in a day :-)

#2.  Do suppressors actually drop sound levels down to where "all you
#hear is the slide".  This is noted in "Marked For Death" and some
#reviews I have read of the HK MP5KSD.

Yes.  As long as the bullet is subsonic.  The loudest sounds coming
from the MAC-10 is the sound of the bolt slamming against the stop
and the sound of the bullets hitting the target - a surprisingly
loud sound!

#3.  Are the non destabilizing suppressors available for long arms
#these days?  Last time I checked a good suppressor ( which was about
#1.5 feet long and 4 inches around ) dropped sound levels by about 25db
#and caused a .5MOA weapon to go to 4-8MOA (!).

The Sionics supressor is not bad considering its intended application.
The myth of a silenced long range sniper rifle is just that - a myth.
That any long range sniping bullet will be supersonic is only one
consideration.  But for clearing buildings and close in defensive
operations, a silenced pistol cannot be beat.

As a second point of interest, my friend also has a silenced Ruger
.22 target pistol.  If one holds the bolt shut, the sound from the
gun goes sorta "pfffft".  If the bolt is allowed to operate, there is
a little bit of a pop from the breech and some mechanical noise
from the bolt.  In either instance, the gun is more than accurate enough
to dispatch pesky cats at up to 20 or 30 yards or so.

John


#It's been a long time since I've really looked into suppressor technology,
#which is a matter of curiousity with me, and since I've last looked it
#seems that it has improved a great deal...any comments?

#Brian

From: John De Armond
Subject: Re: Full auto suppressors?
Organization: Dixie Communications Public Access

rdh@sli.com (Robert D. Houk) writes:

#me....
#   The Sionics supressor is not bad considering its intended application.
#   The myth of a silenced long range sniper rifle is just that - a myth.
#   That any long range sniping bullet will be supersonic is only one
#   consideration.  But for clearing buildings and close in defensive
#   operations, a silenced pistol cannot be beat.

#Um, well, not quite. There are two very signicant advantages to using
#a "silenced sniper rifle". One, the suppressor (if properly purged of
#oxygen first by, e.g., precharging with nitrogen/etc.) will suppress
#the muzzle flash - thus helping "supress" knowledge of where the shot
#came from.

Charging with nitrogen has little if any practical effect.  A properly
designed supressor will supress the muzzle flash without help.  I
rather suspect that the tiny volume of gas space in a supressor compared
to the volume of propellant gas would contribute little if anything to
the flash supression.

#Second, while the muzzle blast is indeed suppressable, the supersonic
#crack of the bullet is not... *but* without the muzzle blast to help
#"triangulate", and using only the "crack" of the bullet flying along on
#its merry little way, people tend to "locate" the source of the shot
#roughly perpendicular to the trajectory of the bullet - thus also helping
#"suppress" (or at least obfuscate) the origin of the shot.

I've heard that theory promoted but in my personal experience it
does  not hold true.  I've sat downrange while a friend fired a
supressed M-14 at a target nearby to satisfy my curiosity.  The
sound appeared to me to "walk" back toward the shooter.  I had
no trouble determining roughly where the shot came from even
with my eyes closed.   That's all that's really required because
assuming the guy misses with the first shot (and that's the only
instance where it's of personal interest :-), I'd be looking
toward his vicinity for the subsequent shots.

The supressor DOES help but not nearly the amount credited it.  I cannot
comment on the instance of being off to the side by some distance while
the sniper is firing at another target as I've never been in the
situation.

My experience is, of course, with one gun and one supressor and one
situation.  Your mileage may vary.

John

From: John De Armond
Subject: Re: noise suppressors
Organization: Dixie Communications Public Access.  The Mouth of the South.

ieeug464@eagle.oscs.montana.edu writes:

#I am interested in finding teckniques of silencing a firearm.  Mostly I would
#like to silence a .22 but I also have a .308 that I woulden't mind quieting
#every now and then. Any info on silencers and other types of noise suppressors
#would be greatly appreciated.

This probably isn't a direct answer to your question but it is funny
so what the heck.

I was recently in one of the indoor ranges I infrequent.  I saw one
of the counter droids busily stuffing styrofoam worms down the neck of
a quart pop bottle.   A little later this guy comes walking up to
the line with this bottle duct-taped to the end of a bolt-action rifle,
probably a .30-06 from the report :-)  He's obviously tried to
make one of the improvised silencers popular in various books.

He aims the rifle down range, pulls the trigger and....

	Worms went EVERYWHERE.

The bottle burst, the report was as loud as my .308 NATO pistol and this
guy had a look on his face like he'd just heard his momma ain't his .  I
only wish I had a camera.

Lesson one:  These things may work on .22s but definitely not large
caliber rifles.

John

From: gmk@falstaff.MAE.CWRU.EDU (Geoff Kotzar)
Subject: Re: noise suppressors
Organization: Case Western Reserve University

In article <54018@mimsy.umd.edu> george@cs.purdue.edu (Michael J. George) writes:
#
#In article <53978@mimsy.umd.edu>, jgd@dixie.com (John De Armond) writes:
#
##
## The bottle burst, the report was as loud as my .308 NATO pistol and this
## guy had a look on his face like he'd just heard his momma ain't his .  I
## only wish I had a camera.
##
## Lesson one:  These things may work on .22s but definitely not large
## caliber rifles.

#
#I recently heard that if you put a 2-liter bottle to your muzzle and shoot
#(through) the bottom, it will work as a one-shot sliencer
# (this is probably what
#you are referring to above).  Well, we tried this with a .357Mag and a .40S&W.
#It was pretty cool that it *did* work.  Just a dull thud and that was it.  I
#would guess that with sub-sonic loads, it would be even more quiet.  We didn't
#fill the bottle with anything, just taped it to the shooting stand, put the
#muzzle to the neck, and fired.
#--
#Michael George
#george@cs.purdue.edu

Please be careful here. When Neal knox was testifying before Congress during
the '86 hearings on gun control, he had an individual who held the necessary
class III paperwork make an adapter to mount the pop bottles on some gun. He
noted at the time that the plastic pop bottle did not constitute a restricted
item but the adapter did. Simply possessing it required the same licensing as
a full silencer. What you are doing may be very goddamned illegal and there are
enough ethically-challenged assholes on the government payroll who would like
nothing better than to advance their careers by making an object lesson out of
you.

geoff kotzar

From: gmk@falstaff.MAE.CWRU.EDU (Geoff Kotzar)
Subject: Re: noise suppressors
Organization: Case Western Reserve University

In article <54252@mimsy.umd.edu> george@cs.purdue.edu (Michael J. George) writes:
#
#In article <54205@mimsy.umd.edu>, gmk@falstaff.MAE.CWRU.EDU (Geoff Kotzar) writes:
## >I recently heard that if you put a 2-liter bottle to your muzzle and shoot
## >(through) the bottom, it will work as a one-shot sliencer
## > (this is probably what
## >would guess that with sub-sonic loads, it would be even more quiet.
## >We didn't
## >fill the bottle with anything, just taped it to the shooting stand, put the
## >muzzle to the neck, and fired.
##
## Please be careful here. When Neal knox was testifying before Congress during
## the '86 hearings on gun control, he had an individual who held the necessary
## class III paperwork make an adapter to mount the pop bottles on some gun. He
## noted at the time that the plastic pop bottle did not constitute a restricted
## item but the adapter did. Simply possessing it required the same licensing as
## a full silencer. What you are doing may be very goddamned illegal and there
## are
## enough ethically-challenged assholes on the government payroll who would like
## nothing better than to advance their careers by making an object lesson out
## of you.
#
#By your own statement, what I did was *not* illegal.  We used plastic pop bot-
#tles taped to the shooting bench.  I suppose you could then try to consider the
#tape to be a restricted item, but I don't know if anyone would buy that.  Also,
#keep in mind that this was done twice, on one occasion, at a private shooting
#range.  We *do not* consistently shoot with this manner of noise suppressoin,
#or *any* manner of noise suppression for that matter.
#
#Michael George
#george@cs.purdue.edu


Whoa, pardner. By my own statement? There is not a court in the land that
will accept what I say as a legal standard, and I do not run the Bureau of
Assholes, Thugs and Fascists. As far as I am concerned, if you did not use
it to harm anyone or deprive anyone of what is rightfully theirs then it was
not illegal, but the BATF may not see it my way.

If you do not presently belong to the NRA you should join, but in the mean-
time get hold of the March, April and May issues of either the American
Rifleman or American Hunter. There are some articles and letters reporting
the current round of abuses of law abiding citizens' rights by the BATF.
They can batter down your door, torch open your gun safe, trash your home
and, after finding nothing illegal, leave everything standing open with a
simple note saying "found nothing" pinned to your door. The individuals to
whom this happened will probably have to sue the government to recover
damages, if they even can. I seriously doubt if anyone's homeowners insur-
ance covers Gestapo raids.

You have as much as admitted on a public forum that you have dabbled in the
occult. If THEY are listening in and choose to accept your explanation then
you have no problem, and if they don't your ass is theirs. In a truely free
society you could speak freely without fear of government reprisals. It is
truely sad, but you should be a little more discrete on the net.


geoff kotzar        gmk@falstaff.mae.cwru.edu

From: John De Armond
Subject: Re: Full auto rate of fire
Organization: Dixie Communications Public Access.  The Mouth of the South.

fountain@bach.udel.edu (Eric Randolp Benson) writes:

##	They made a smaller .380 version, which seems kind
##of more silly.
#Not totally.  They describe the Mini-uzi pistol as having the best
#qualities of an electric drill and a pistol.  At least with .380, you
#don't have quite the recoil problem.

A friend of mine has a full auto Mac-11 in .380 complete with supressor.
This is an imminently practical weapon.  There is essentially
no recoil and the sound of the bullets smacking a tree are louder
than the report.  The gun is steady enough that 2 and 3 round bursts
can easily be squeezed off - something almost impossible with its
big brothers.  At full chat, holding with one hand AND keeping the
burst on target is pretty easy.  While the .380 is kinda puny shot
one at a time out of a pistol, it seems to be an ideal full auto caliber.
I've shot 9mm Macs and I owned a .45ACP one.  Neither were nearly
as fun to shoot nor as easy to control as the .380.

John

From: mjalava@ahti.hut.fi (Mika Jalava)
Newsgroups: rec.guns
Subject: Re: Alternatives to Silencers
Date: 2 Feb 1995 17:29:27 -0500
Organization: Helsinki University of Technology
Lines: 64

In article <28JAN199523143253@utkvx.utk.edu>,
Bite Me ATF <staywet@utkvx.utcc.utk.edu> wrote:

#the 2 liter coke bottle screws onto the gun...

When it is relatively easy to make a working and lasting real
suppressor, why mess up with these coke bottle and duct tape things?
If you are going to do something illegal anyway, why not do it
reasonably well :-)

For starters, I am not suggesting you make anything against the law.
Remember, though, that at some places suppressors are not prohibited,
so this may be of use for some of you. If you have to pay a high tax
to have a legal suppressor, I suggest you buy a good commercial one,
though. 

An easy starting point for a suppressed pistol is a Ruger MKII heavy
barrel version. Any other gun with round, thick barrel will work as
well (I tried this with plastic/aluminum parts and an old .22 lr rifle with
extremely heavy barrel).

Get plastic, aluminum or steel pipe (your choice, depends on how long
you want the thing last) that has the same inside diameter as the
barrel's outside diameter. Cut it to the length you want plus about
2". The longer the suppressor, the more effective it will be at least
to a certain point. This simple design needs to be a little longer
than the commercial products that have better shaped baffles and
probably larger diameter. In the .22 rifle, 20 cm (about 12") was
enough to reduce the noise to a little puff. A pistol will need a
somewhat longer tube. You may experiment with this.

Cut round baffles from an aluminium or steel sheet that just fit
inside the tube. Drill holes in the center. The holes need to be
larger than the caliber of the gun, as the suppressor isn't easy to
fit exactly straight with the barrel (and they need to be slightly
bigger anyway). I used 8 mm for .22 lr. I don't know what is the right
space between the baffles, but I used 2 cm (4/5").

Then get tube with the outside diameter the same as the inside
diameter of the first tube. Cut it into pieces to separate the
baffles. Put a longer tube before the first baffle to leave an
expansion chamber after the muzzle. I used 5 cm (2"). Attach the
frontmost baffle permanently (glue, weld or use some other method
again depending on how long you want the thing last). Drop the pieces
of the smaller tube and the baffles into the bigger tube. Glue or weld
the last, longer piece in place. This must be shorter than the space
in the back to leave room for the muzzle.

Cut an opening for the front sight to the tube. Slide the suppressor
on the muzzle and _check the alignment with the barrel_! I have no
good methods to correct a badly aligned tube, so be careful with the
work in the first place.

You can use a pipe clamp or some other device to tighten the
suppressor in place. You can also use bayonet mounting, cut the
opening for the front sight so that you can twist the suppressor to
securely mount it when it is fully seated. If you use steel pipe, you
need to use some softer coating inside it to prevent excessive damage
to the finish of the gun.

	Mika

From: wilska@mopo.cc.lut.fi (Panu Wilska)
Subject: Silencers Was: please read etc..
Organization: Lappeenranta University of Technology, Finland

pdunkel@vipunen.hut.fi (Paul Dunkel) writes:

#I own a couple of VAIME's silencer, is there any better ones?
#I have also later self made some to .22 and 7.65, but even if I started
#with some relative small sized, they ended up to same measurements as
#those VAIME's ones. Is it possible to make small ones?

Vaime represents "normal" silencer design in terms of technical solution.
I've seen and tested VAIME in .22, it was wery good as most silencers
designed for .22 . It might be interesting to test VAIME for larger caliber
if such silencers show around.

Those VAIMEs I've seen had plastic internal middle-plates, to my opinion
that is quite optimistic solution. I can imagine them melting in heavy
use or when using larger calibers with more powerful muzzle flash. (?)

Some manufacturers like Parker-Hale use a kind of steel spring inside the
silencer housing to do the same as the plates. I quite don't like that
solution because there seems to be a kind of "leak" of noise between
that spring and silencer housing. (that is just a personal opinion
by practice)

The optimum size for silencer is as you noticed quite constant for
each caliber and silencer diameter. The space can be spared by adapting
new thinking on where that space is needed.

I mostly use Reflex-supressors by BR-Tuote, they
are arranged so that the extra space needed for silencer is only one third
of silencers lenght. The silencing effect is brought thorugh circulating
gas-blow backwards before letting it go through the middle plates ( I don't
know better translation) that are part of conventional design. This works
best with supersonic bullets, for subsonic ammo conventional design with
fixing the silencer to front screws and having the whole lenght of silencer
being with those plates and in front of muzzle may work as well or even better.

             (-----------------------(--(--(--(
 1           (                 2     \  (3 (  (
===================================
===================================
             (                       /  (  (  (
             (_______________________(__(__(__(


This is (poor) illustration of sparing some space with Reflex-supressor.

1 is barrel 2 is the point where it has fixing with supressor
3 represent those sound supressing middle-plates (please give them
better translation)

So the barrel comes into the silencer in a kind of "tube" that is attached
to silencers shell. The space that is left behind the barrels muzzle
is for gas-circulating. This solution, doesnt of course work on most
pistols as it needs "open" barrel but is very handy with rifles,
sub-machine guns and so on.

In this design the critical thing is how to profile the first middle-
plates to get most of the exhaust gases to circulate backwards.

Good point in this solution or at least how they are made by BR is that
those silencers are totally maintenance-free and they can sustain
unlimited full-auto-fire. (In tests conducted by Finnish Army the barrel
of Valmet M62 melted before silencer had had any damage.) The material
used in that device is stainless steel.

Silencers can be made short, but that normally demands larger diameter
and therefore sometimes also different centering to avoid blocking the
line of sight. I've seen really short silencers in 9mm pistols, short
because tilting barrels don't accept too much weight at muzzle to
function properly. Those tend to be quite noisy, but when working with
semiautomatic you always have some noise from reciever etc.

One correction to previous posting:

There are also some older and also special silencer-designs that really do
reduce velocity, but there is a good explanation for that:

1. Some guns need full-power(supersonic) ammo to function properly. So if
you want to silence them well you need a silencer that really slow down
the bullet after leaving the barrel itself.

2. There are also some poor designs that are just tubes filled with some
stuff that allows the bullet to go through, (steel wool etc.) but
doesn't have plates or anything like that. These things are
mostly short-living, dangerous and affect both velocity and accuracy.

##There is so much bullshit about silencers in this newsgroup that there
##might be need for FAQ about this subject.

#Looking forward for it...

#Paul

That requires some team-work I think. Anybody interested to help to make
the question-list and comparing possible answers?

Panu Wilska

From: wilska@mopo.cc.lut.fi (Panu Wilska)
Subject: Re: Silencers legal?
Organization: Lappeenranta University of Technology, Finland

markc@CSOS.ORST.EDU (Mark Cook) writes:

#Michael Carter (mcarter@scf.usc.edu) writes:

## ulms@rzstud1.rz.uni-karlsruhe.de (Livius Halupczok) writes:
##
## #I have a question concerning US weapon laws:
## #
## #Is it possible to buy a silencer if you have a gun permit?
##

Just for comparison for the subject here are some facts how
silencers are treated in Finland.

Silencers are not considered to be "parts of a firearm", that means
that anyone can build one, own one and buy or sell one without any
restrictions. Just as grips or scopes.

There are no special taxes on silencers, of course for everything you buy the
22% VAT is included.

Silencers have been found useful in preventing noise-pollution of shooting
ranges that are near urban areas. Several studies have been made on subject
should silencers be obligatory. One study made by State Department of Labor
strongly suggests people to use silencers to prevent damage to their ears.
(that state department handles issues of work safety etc.) One result of
those studies is that the new assault-rifle of Finnish military is capable
of fitting a silencer.

The speciality in silencer-research is so called Reflex-technology that
is designed for supersonic bullets. The supersonic crack of a bullet can
not be silenced, but the noise what comes to shooter's ears is considerably
lower. For example Valmet M62/76 7.62x39 sounds like a .22 when using
such supressor with normal velocity bullet. For military purposes that type
of silencers are handy as they "hide" the direction of the shot as it seems
to come from "everywhere" People more interested in that
subject may be interested to read "Special Weapons" 1/94.

Silencers are cheap and of high quality in Finland. You can buy a silencer
for .22 for $50 and top quality silencers that sustain unlimited full-
automatic fire go for about $150. Factory-made silencers are available
actually for any gun and caliber. (even for such rarities as MG-34, MP-40,
Maxim, etc. you name it!)

Recently there were research on shotgun- silencers. That study pointed
that only subsonic loads can be silenced effectively as there are so many
supersonic cracks in one shot. So the situation is much different from
single bullet with only one sonic crack.

Silencers are coming increasingly popular, more and more .22 are being
sold with silencer already fitted. For Ruger mkII there are numerous solutions
some with bayonet-style fixing wich make it fast to fix and remove. Such
solutions have been seen on Luger and Margolin.
Almost all gunsmiths can make silencers.
The best known industrial makes are VAIME, KANU and BR-REFLEX.

Finally what comes to regulations on guns, one can obtain a license for
hunting or sports (including both target and practical) at local
police. The procedure takes between 1 - 2 weeks. If there is no criminal
background and one can point a range he is allowed to shoot there is
normally no problem. For military firearms (full-auto etc.) you must
apply your licence from state (state is more close to American definition
of county in Finland) police officials. That is more difficult and normally
only collectors get those licences and they are quite strictly enforced.
However the system works quite well.

One funny thing: One can not buy a firearm for self-defence. That is not
acceptable reason. (well, taxi-drivers and guards get) Mace and other
gases are considered as firearms and are not available for public.

Panu Wilska

From: John De Armond
Newsgroups: rec.pyrotechnics
Subject: silencers
Message-ID: <21161@rsiatl.Dixie.Com>
Date: 16 Aug 91 15:30:59 GMT

jkh@meepmeep.pcs.com (Jordan K. Hubbard) writes:

>Errm, a suppressor ("silencer" being a purely hollywood invented term)
>DOES NOT lower the speed of the outgoing round at all.  This would, in
>fact, be extremely dangerous to attempt!  Any method you could use to
>slow down the round would invariably create a certain amount of
>back-pressure, which would screw up all your pressure curve formulas
>and make it possible for previously safely loaded rounds to destroy
>the weapon (and perhaps the operator as well).

Not true at all.  The barrier-type (Sionics?) type silencers that use
wads of metal wool separated by rubber wipers extract significant
velocity from the bullet.  Out of curiosity about this very subject,
a class III dealer friend and I recently set my chronograph up and
measured the velocity of a silenced Ruger .22 pistol with and without the
silencer.  With new rubber baffles, the silencer cost almost 200 fps in
velocity.  We'll try it again after he shoots the thing loose.  We'll
also be looking at a supressed 9mm Mac-10.  I agree that the velocity
loss is not the primary goal of the rubber baffles.  The baffles serve
primarily to "wipe" the sound from the rear of the bullet by closing
very rapidly behind it.  The device does generate additional pressure
in the barrel, sufficiently more that my friend had to polish and hard
chrome the chamber to get it to extract properly.  I can also comment
that with new baffles, this device fully qualifies as a silencer, as the
loudest sounds are the hammer falling and the bullet smacking the target.
The Mac-10 is a bit louder, sounding like someone softly clapping their
hands.

From: Gale McMillan <gale@mcmfamily.com>
Newsgroups: rec.guns
Subject: Re: Silencer on SKS?
Date: 24 May 1998 21:47:38 -0400

The work I did on m14 suppressors taught me that it is very difficult
io suppress a gas operated rifle because of lingering pressure at the
time the bolt opens. A number of problems must be over come before it
will funtion any where near normal. I would not undertake an SKS ecause
the end would not be worth the effort.
Gale McMillan