Square bore on a suppressor?

[pneumagger]

So I guess Liberty makes a can with a square bore (the holes in the baffles are square).
Evidently, if marketing is to be believed, it works very well.

Why does this work so well? Are there other features offering the good suppression or is it primarily the square bore? Does it only work with high pressure rifle rounds? It certainly is interesting, to say the least.

[doubloon]

Is the blast baffle square bored too?

Could be added turbulence ?

Could just be good marketeering. If you can find some independent meter numbers for a liberty can with a square bore against a "normal" bore can with the same volume on the same host that would at least help decide if the topic is worth perusing more in depth.

[pneumagger]

Is the blast baffle square bored too?

Could be added turbulence ?

Could just be good marketeering. If you can find some independent meter numbers for a liberty can with a square bore against a "normal" bore can with the same volume on the same host that would at least help decide if the topic is worth perusing more in depth.

viewtopic.php?f=2&t=63403
This is the thread where I saw mention of a square bore. 35dB measured as reported on NFAtalk.org
I dont want to talk about the actual "Liberty Suppressor" so much as I want to discuss square bores.
It's certainly innovative thinking and I'd like to understand it better.

I wonder if it would work on lower pressure suppressors like 9mm, 45, & 22lr.
Hitting a round hole baffle with a sqare or triangular corner file seems pretty easy if it boosts performance.
Or am I thinking too simplistic?

[doubloon]

Sorry, it wasn't my intent to suggest a comparison of the Liberty to everything else.

I understood the question.

My suggestion was more just a simple square bore volume compared to a round bore of equal volume. My point being maybe square bores don't really work as well as round bores period and a simple dB comparison should root that out assuming baffle design is similar.

If square or triangular works better than round I don't see why squaring off a round bore wouldn't be a simple way to get more efficiency out of the can.

If it works maybe it's not so much actually more suppression as it is frequency shifting ala the "Hush Hole".

[Mageever]

Only testing would really tell you. And may be very design dependent.

The chief worry for me would be the stress induced by sharp corners in the baffle. A corner like this causes a "stress riser" in the baffle and I think a lot of extra material would have to be added to keep it from cracking. The
De Havilland Comet was the first commercial jet airliner and it was brought down by its square windows that cracked the fuselage.

[Chondro]

I only know of the Liberty cans with the square bores and what Dave has told me. Without discussing those it limits what I could add to it. I can tell you Dave doesn't do anything for marketing..He's a master at everything cans but marketing is not his area. Alot harder to do than round holes. I found with his other cans when you see something as different as say a square hole there is 10 other reasons he went to the trouble of doing it and just doesn't bother to explain why. He only recently added to his webpage about the lack of blowback in the Kodiaks. Given the time and thought that went into that you would have thought it would be mentioned from day 1. The square bores are even in their Torch now with no mention of it.

I had asked about triangles as well..Doesn't seem to work.. I'd add something about thinking out of the box but just to easy..

The really screwy thing..the square holes are made after its assembled..I gave up on trying to figure that one out..

[TNPittbull]

wire edm'd the holes square after assembly would be my guess.

[pneumagger]

Gotta be a wire edm or a square broach. I couldn't see broaching being precise enough though.
Do all the squares have to line up?

[Fireman1291]

Since we are thinking outside the box....what about a star shaped bore hole? A very tight one, I wonder if that would do anything. Or a mix of round and star? hmmm

[chrismartin]

Since we are thinking outside the box....what about a star shaped bore hole? A very tight one, I wonder if that would do anything. Or a mix of round and star? hmmm

[Chondro]

Now that does look cool.. Oh and Dave was just screwing with me about the squares added after the can is made..

After he let me think about it a bit then he added:
The square holes are not added after assembly. They are put in during the making of the core to make them available for deburring.

[Historian]

Well, Chondro, as " ... The really screwy thing..the square holes are made after its assembled..I gave up on trying to figure that one out.."
I surmise that he really does not want to BROACH that subject.

I wonder what a Saxophone would sound like if its cross section was SQUARE, JACKSON! [ Argot of
Jazzmen who played in the 30's. ]

Great day.

[Fireman1291]

Since we are thinking outside the box....what about a star shaped bore hole? A very tight one, I wonder if that would do anything. Or a mix of round and star? hmmm

.........................F--k...........LOLOLOL

[Illuminated_one]

Since seeing their square bore silencer, I've wondered if rotating every other baffle/square 45 degrees (so you have square-diamond-square-diamond-etc) would make any difference.

[CKOD]

Now that does look cool.. Oh and Dave was just screwing with me about the squares added after the can is made..

After he let me think about it a bit then he added:
The square holes are not added after assembly. They are put in during the making of the core to make them available for deburring.

Not EDMed if it needs deburring. though EDM does leave very sharp corners so you could call breaking the corners deburring.


It could be milled if there is a radius on the corners, for sharp corners with a small radius, its either traditionally broached, or if they are full of win
http://www.slatertools.com/rotary9.htm rotary broached on a lathe.

In for people being very confused as to how the above rotary broaching works

Oh and for those who want other shapes,

http://www.slatertools.com/rotary11.htm star shaped, both pointed and rounded

http://www.slatertools.com/rotary8.htm hex, also good for hexagonal holes in endcaps

[Bowen1911]

I would think there would need to be a small radius in the corners, because a sharp corner is a great place for stress concentration => failure

[Kevin/AAC]

Maybe it works, but it seems goofy. I have my doubts.

An easy test to prove the theory would be to build two silencers exactly the same...except for square and round bores.

[Wicked]

Additional suppressive effectiveness (or not) aside; I'm betting on the formation of stress cracking in square/sharp corners.

[Chondro]

Guys its all been done already..

[Bowen1911]

being done is one thing

being more effective is another.


I could see it maybe being more turbulent, but i dont know

[doubloon]

Maybe it works, but it seems goofy. I have my doubts.

An easy test to prove the theory would be to build two silencers exactly the same...except for square and round bores.

Hmmm ...

If only there were someone in a position to create two cans exactly the same except for the square bores. Maybe someone who worked at a suppressor company.

[Bowen1911]

Maybe it works, but it seems goofy. I have my doubts.

An easy test to prove the theory would be to build two silencers exactly the same...except for square and round bores.

Hmmm ...

If only there were someone in a position to create two cans exactly the same except for the square bores. Maybe someone who worked at a suppressor company.

and maybe someone willing to show the results....

[Chondro]

Ask Dave what his numbers were on his cans before he changed the design..

[Kevin/AAC]

Maybe it works, but it seems goofy. I have my doubts.

An easy test to prove the theory would be to build two silencers exactly the same...except for square and round bores.

Hmmm ...

If only there were someone in a position to create two cans exactly the same except for the square bores. Maybe someone who worked at a suppressor company.

I would never waste my guys' time with something like this...

[telsonman]

Maybe it works, but it seems goofy. I have my doubts.

An easy test to prove the theory would be to build two silencers exactly the same...except for square and round bores.

Hmmm ...

If only there were someone in a position to create two cans exactly the same except for the square bores. Maybe someone who worked at a suppressor company.

I would never waste my guys' time with something like this...

How is it a waste?