Page 2 of 6

Posted: Thu May 07, 2009 11:00 am
by psycix
Well, I watched the whole documentairy. It is indeed very basic. Lots of crap of how to attach it to your barrel and how they are assembling all those parts which just happen to fit together.

A few interesting things are shown, but it would be nice if they told why.
Like first they use a chamber with steel wool, and then baffles and then a wipe. Sure, but WHY? Why not in reverse?

Posted: Sat May 09, 2009 3:10 am
by jackssmirkingrevenge
I agree it's a bit dragging but as I said, it's a start for people with no idea of the concept.
psycix wrote:A few interesting things are shown, but it would be nice if they told why. Like first they use a chamber with steel wool, and then baffles and then a wipe. Sure, but WHY? Why not in reverse?
This is how many commercial silencers are built, with a large expansion chamber do drop the pressure first, then a baffle stack.

Image

A wipe at the end makes sense because it means that gasses can't escape before the projectile punctures the wipe, allowing them maximum time to cool down and expand. TheWelrod of WW2 fame and beyond used such a system to great effect.

Image

Posted: Sat May 09, 2009 12:34 pm
by THUNDERLORD
... I agree there, especially with some of the better suppressed 0.22" riflesout there.
That was more like it!
Although I've seen quiter still!

The trick is to not get discouraged, I tried bottle tops one time, did nothing, A plastic soda and tape failed to supress a .32...Then imidiate disposal afterwards was a pain too! :P

Posted: Wed May 27, 2009 10:26 am
by THUNDERLORD
I ran out of time on that last reply, just noticed it went through right as the computer cut off, (thought it hadn't).

Any way, another idea besides a silencer, is to combine the shot noise with another noise that sounds more industrial and common in populated areas.
Like Maybe a gas engine (chain-saw sounding toy model motor etc.) or small power tool, loud electric motor etc....Then BLAM following/during shots isn't as obvious. (backfire, tool noise, breakage???)

A rotary tool like a dremel at the 28-30000 RPM range setting with a metal blade about 5 inches long on a metal plate backing gets pretty loud GRRRR VrRRRRRR GRRRR... followed by a pop probably wouldn't cause much alarm as just the bang alone. (careful the metal isn't going to fly apart from centrifugal force, also poor balance can mess up the bearings)
Like when workers are jackhammering I am always thinking Dang, "The possibilities" :P

Really though, I was demonstrating to a friend that a .22 doesn't cause much alarm anyway even in a very populated area, by smacking .25 nail gun blanks with a hammer in the middle of a street. (Raised no attention at all)...interesting.

Also with the rubber baffles sandwiched between metal, there is a safety advantage that if the projectile strays a little (or is fired from a smoothbore), it probably won't stray enough to smack the metal washers with much larger hole , and still make it through the next rubber washer with smaller hole than projectile diameter.

BTW, There was a production chinese pistol very similar to diagram of the English one above only with rubber baffle design.
The baffles were replaceable too.
Americans (and probably others) should keep in mind that possesion of all specific parts to a silencer (or whatever), Is the same as possesion of the assembled part.
So, ...the noise generator idea might be better IMO. 8)

Posted: Wed May 27, 2009 10:41 am
by jackssmirkingrevenge
THUNDERLORD wrote:BTW, There was a production chinese pistol very similar to diagram of the English one above only with rubber baffle design.
There's the Type 64 or its successor, theType 67 which was featured in prominently in L4YER CAK3along with the Welrod ;)

Designed for low noise.

Posted: Wed May 27, 2009 11:44 am
by Technician1002
I know the old timers have seen this, but in spudding a small chamber (larger barrel) goes a long way to suppression as the muzzle blast is minimized. I was working on getting a TB launcher very quiet with little success until I went extreme on on the barrel size. The result was at high pressure the valve opening is louder than the muzzle blast.

Presenting again, the marshmallow cannon with the 7 foot tennis ball barrel. The video is simply listed as a tennis ball hang time for general youtube audiences. Most won't pick up on the fact it's almost silent.

[youtube][/youtube]

The thread on the quest for quiet is here;
http://www.spudfiles.com/forums/failed- ... 17989.html

Posted: Tue Jun 09, 2009 7:11 pm
by THUNDERLORD
Almost out of time for today, but I noticed a component that would probably be good for traditional type cone shaped baffles.
It's fence caps that go on the top of chain link fence poles.
They come in different diameters too.
I was looking at them before, to convert into motorcycle turn signals myself.
Maybe about 8 or 12 (+) would work OK.

Got to go :cry: 8)
edit: Just got 30 more minutes!!!Wooo!!!
Yeah, the cones should point inward to the muzzle.
They are some type of cast or potmetal, so if a shot strays it would probably just blast through them.
Also they have a round shape inside (from casting(?)) that looks like center.
No interest in sound suppressors myself, Just the theory, in case the poop really hits the fan one day! :twisted: 8)

Posted: Tue Dec 07, 2010 3:13 am
by LovableAirGuns
for some reason the video wont work :(

Posted: Tue Dec 07, 2010 3:26 am
by jackssmirkingrevenge

Posted: Tue Dec 07, 2010 4:19 am
by Selador
THUNDERLORD wrote: Also no mention (I noticed) of using rubber baffles sandwiched between metal baffles (or fender washers) a method that is capable of reducing the sound enough to hear the firing pin strike and ejection/ slide spring only.
Can anyone shed more light on this ?

Posted: Tue Dec 07, 2010 4:27 am
by LovableAirGuns
thanks you so much i have viewed this topic so many times hoping the video would work until i decided to make comment :D

Posted: Tue Dec 07, 2010 4:46 am
by Technician1002
Can anyone shed more light on this ?
The rubber bullet wipe is covered in the video. It makes the hole smaller than the bullet for the gas so less goes through. The bullet pushes through so the hole in the bullet wipe enlarges to allow passage of the bullet while providing additional noise suppression to the gas flow.

Posted: Tue Dec 07, 2010 4:51 am
by jackssmirkingrevenge
Selador wrote:Can anyone shed more light on this?
Have a look at the Welrod's integral suppressor:

Image

Posted: Tue Dec 07, 2010 1:06 pm
by Selador
Technician1002 wrote:The rubber bullet wipe is covered in the video. It makes the hole smaller than the bullet for the gas so less goes through. The bullet pushes through so the hole in the bullet wipe enlarges to allow passage of the bullet while providing additional noise suppression to the gas flow.
Thank you.

I was hoping to avoid having to download a 45 minute video.
jackssmirkingrevenge wrote: Have a look at the Welrod's integral suppressor:
Thank you.

I could certainly build that.

Seems like it would slow down a projectile from an airgun, a bit too much, as-is.

But it certainly gives a good idea of the princple and engenders ideas.

:D

Posted: Tue Dec 07, 2010 1:15 pm
by jackssmirkingrevenge
One must stress again the difference between airguns and firearms, for the former volume is of much greater importance for effective sound suppression.
Seems like it would slow down a projectile from an airgun, a bit too much, as-is.
Not necessarily the case with suppressors, I had done a test with my Daystate and the factory suppressor actually increased velocity.

Data is for two 5 shot strings with and without suppressor. In between strings I refilled the rifle to the same pressure. Here are the results in feet per second:

without suppressor - 860, 860, 870, 869, 872 (866.2 average)

with Daystate Airstream CF suppressor fitted - 877, 880, 884, 882, 883 (881.2 average)

This gives an average increase in velocity of 15 feet per second - in practical terms, an insignificant increase, which you'd never notice without a chrony, but interesting nonetheless.