Mini-can 140 dB = still loud, but not instant hearing damage

[wacki]

I'm considering a DIY custom build mini-suppressor (w/ form 1) to make long trips to the range easy on the ears (still wearing 33 NRR muffs and plugs of course) and easy on the girlfriend while still being super small and nimble. I'm open to just about any design suggestions. Goals are outlined below.

Question set #1: Anyone know how much suppression you would get on 9mm with just a blast chamber and a single K baffle? What about the same setup in a wider rectangular tube? I'm just getting into this stuff.
Question #2: How big of a size difference will there be for a 9mm suppressed to 140 vs 152 dB. I might end up building two.
Question #3: Any math guru's know how to calculate this stuff?

Mission Statement
To make a durable, small suppressor that works just well enough to make the girlfriend or hearing loss centers happy.

Size & Weight
As small and compact as possible. This should be comfortable for all-day use at the range.

Minimum spec = 152 dB - Keeps the woman happy
The girlfriend can't stand being around the super loud pistols. .22 LR produces a 152 dB shock wave. The girlfriend likes those. As 9mm is 160 dB, that's 8 dB in reduction just to make the girlfriend happy. If she is happy, I get to shoot more.

Optimal spec = 140 dB - Meets NIOSH impulse sound limits & matches local shooting range background noise
To make NIOSH / CDC hearing loss center happy I'm guesstimating from their exposure charts that i need to get it down to 140 dB which is the internationally recognized maximum for impulse noisees. NIOSH allows between 22 and 27 seconds of nonstop exposure at 127.25 dB which is what you would get *if* you are wearing just ear muffs as I always do. That's a lot of range time.... if you are shooting alone. Anything beyond this means I made the suppressor too big and can shave off some weight.

High performance suppression is not needed when people are shooting unsuppressed 10-12' away.

To put that in perspective, the Osprey hits 125 dB dry w/ 9mm. That's overkill for my purposes. 35 dB is a LOT more than I need as it's way below my ranges background noise.

Added bonus, if I have to use the pistol for a self defense and I'm not wearing muffs my ears might be unharmed.


Durability
Must be able to handle a full day at the range. That's 500 rounds in a sitting. NO short term wipes, just metal baffles. Minimum suppression specs should be attained without the use of a wetting agent.


MATH
=============
As per NIOSH protocol, assuming 75% efficiency with my 33 NRR Pro-Ears which is 24.75 dB of protection.


152 dB (for .22 LR) - 24.75 dB (Pro-Ears) = 127.25 dB that hits your ear drum. According to NIOSH you can handle about 1 second of that.

[SRM]

You could make it pretty small with only four or five baffles.
I`m not sure one baffle would do much. A large blast chamber is gonna have frp.

[BLAKE2131]

have you looked at the TM poseidon9

[wacki]

have you looked at the TM poseidon9

The poseidon uses wipes = not good for all day shooting trips. Does not fit the dependable criteria.

Also, they are highly effective. Which means I can make it smaller.

[SRM]

Don`t make yourself dependent to wipes. Pain in the ass.

[LavaRed]

If it can be wet I am confident I can produce a design that offers way more than 140db reduction within the stated envelope.

[wacki]

If it can be wet I am confident I can produce a design that offers way more than 140db reduction within the stated envelope.

Well how small do you think you could make a dry 140 db suppressor?

How small would a dry 152 dB suppressor be for 9mm?

There is about a 100% chance I will build one of these (given that it's legal to do so in Indiana).

[Bendersquint]

You need to quantify a specific factory loaded cartridge so we can see how many dB it will actually need to be.

If you are going to do this why not do it right and get a real suppressor, if not just buy your girlfriend a pair of ear muffs with the $200 you arent paying the gov for a non-silencer.

Your girlfriend will appreciate it more you getting some real suppression not just throwing a toilet paper roll on the pistol to drop it 8dB.

Not instant hearing damage is still hearing damage and women don't like that at all, my wife won't shoot unsuppressed and thinks the 22lr is loud which it is.

[delta9mda]

listen to what bender has to say.

even 139 db is "safe" but after some time you will have damage from this too.

[wacki]

You need to quantify a specific factory loaded cartridge so we can see how many dB it will actually need to be.

I typically buy a case of whatever is cheap at the shows. Last time it was Federal FMJ in 9mm. I'm guessing 115 grain but I don't know as it's not with me.

If you are going to do this why not do it right and get a real suppressor,

Already in the works. I WILL own several. I just want something I can use all day and not notice it on the end of the barrel though.

if not just buy your girlfriend a pair of ear muffs with the $200 you arent paying the gov for a non-silencer.

I own 4 pairs of 33 NRR muffs and 300 plugs. Everyone doubles up. Suppressed or not, I protect my and my friends ears.

Your girlfriend will appreciate it more you getting some real suppression not just throwing a toilet paper roll on the pistol to drop it 8dB.

If you read my post you would realize that I always wear muffs and plugs and I'm designing this thing for use with Muffs.

Not instant hearing damage is still hearing damage and women don't like that at all, my wife won't shoot unsuppressed and thinks the 22lr is loud which it is.

I agree. However, if I wear muffs and plugs and bring the 9mm down to 140 dB I should be OK according to NIOSH.

Look, I WILL own multiple suppressors by the time the year is out. So lets just kill that argument before it starts.

For now just humor me and think of this as an academic exercise. How can it be done? Think of it as a suppressor for IDPA or some other quick shooting match. This is for when speed is essential and you don't want to have a big can hanging off the end of your pistol but you still want to protect your ears.

Again, I WILL own multiple factory made suppressors. Just think of this as a side project to add to the collection.

[delta9mda]

take a look at the tirant 9s (shorty) as a starting point

[Bendersquint]

If you want a quiet can stop buying whatever is cheap, all that stuff is supersonic and won't be anywhere near as quiet as you are hoping.

With all that protection your girlfriend is STILL complaining about 9mm being louder than 22lr?

Sorry I read over your optimal specs paragraph and must have skipped over that part as I have submitted to government contracts that had less detailed requirements. Apologies.

140dB is still damaging levels and will cause permanent hearing loss, even 115dB is damaging and you should be wearing hearing protection, but hardly anyone does.

It can not be done without some advanced baffles.

I have shot IDPA and IPSC with a full sized suppressed pistol that was quiet enough that no ears were needed, speed wasn't affected at all, actually I was faster. i shoot all my matches suppressed and hasn't slowed me down at all, and this is with full sized suppressors.

Basically you are wanting how to design an ineffective sound suppressor that is small to take the bark off. Here are the specs. 1.25"OD x 3 inches long with 3 K baffles, all aluminum. Add a booster on the end of it to cycle your pistol(hopefully).

[wacki]

If you want a quiet can stop buying whatever is cheap, all that stuff is supersonic and won't be anywhere near as quiet as you are hoping.

Ya I'll probably have to start reloading.

Basically you are wanting how to design an ineffective sound suppressor that is small to take the bark off. Here are the specs. 1.25"OD x 3 inches long with 3 K baffles, all aluminum. Add a booster on the end of it to cycle your pistol(hopefully).

Thanks! I guess I could name it the de-barker. A few more questions:

1) Do I have to machine the K baffles myself or do people sell those?

2) Is there a rectangular equivalent? (kinda like the Osprey?)

[wacki]

take a look at the tirant 9s (shorty) as a starting point

That's about what I need. That thing has 18 dB reduction and 6.5" length! I guess that means Bendersquint is right and 3" inches or so will get me my 10 dB de-barker. Maybe if I Osprey it with a rectangular can I can get higher dB suppression.

[Bendersquint]

If you want a quiet can stop buying whatever is cheap, all that stuff is supersonic and won't be anywhere near as quiet as you are hoping.

Ya I'll probably have to start reloading.

Basically you are wanting how to design an ineffective sound suppressor that is small to take the bark off. Here are the specs. 1.25"OD x 3 inches long with 3 K baffles, all aluminum. Add a booster on the end of it to cycle your pistol(hopefully).

Thanks! I guess I could name it the de-barker. A few more questions:

1) Do I have to machine the K baffles myself or do people sell those?

2) Is there a rectangular equivalent? (kinda like the Osprey?)

Reloading is the only way you will get affordable subsonics, you can reload for cheaper than the 'whatever is on hand' you are buying now.

1 - Yes you will have to machine the baffles yourself it is illegal for anyone to sell you silencer parts, there are some thing that can be done but won't be getting into that at this point.

2 - No rectangular equivalent, even if there were you would need to figure out the piston and the mechanics of keeping it upright and not some weird angle, Silencerco figured it out and patented it. You want something cheap then make it yourself easiest is K's with a round tube. Want exptic? Buy a Osprey.

[Bendersquint]

take a look at the tirant 9s (shorty) as a starting point

That's about what I need. That thing has 18 dB reduction and 6.5" length! I guess that means Bendersquint is right and 3" inches or so will get me my 10 dB de-barker. Maybe if I Osprey it with a rectangular can I can get higher dB suppression.

The 6.5" includes the piston, its right about the same size as i was recommending when you include the piston.

Size is no scalable so you can't say 6.5 gives me 18 so around half will give me about half the dB reduction. it doesnt work like that at all.

[BLAKE2131]

you dont have to use the wipes they did that to help keep the media in and not have it go in your pocket

[doubloon]

you dont have to use the wipes they did that to help keep the media in and not have it go in your pocket

It is significantly quieter, even dry, with the end wipe in place than without.

[Bendersquint]

you dont have to use the wipes they did that to help keep the media in and not have it go in your pocket

It is significantly quieter, even dry, with the end wipe in place than without.

Wipes aren't the demon so many portray it to be, only people that really are against it for a justified reason are the machinegun users. Would be a pain changing it out ever 4 seconds.

[57fairlane]

take a look at the tirant 9s (shorty) as a starting point

That's about what I need. That thing has 18 dB reduction and 6.5" length! I guess that means Bendersquint is right and 3" inches or so will get me my 10 dB de-barker. Maybe if I Osprey it with a rectangular can I can get higher dB suppression.

x2 on delta . . .

Just beware with any monocore in a "shorty" length . . . its exponentially harder to get the same suppression in a monocore as it is with Ks once you start really knocking length off. I've tried numerous times and if you somehow manage to get some good suppression out of it, unfortunately by default it seems FRP goes up considerably.

Since this is in silencersmithing, I would replicate a tirant 9s and do a 3 baffle setup. Run it wet and you should be under 140 with good k baffles and a little liquid persuasion.

[wacki]

Is there any magic to wet suppressors? Is it really as simple as adding a few cc's of water to a K baffle design?

[Bendersquint]

Is there any magic to wet suppressors? Is it really as simple as adding a few cc's of water to a K baffle design?

Yes there is some magic to a designed wet suppressor. Just adding water helps a suppressor perform better but doesn't make it a wet suppressor.

Most designed wet suppressors have some cavities that hold the liquid so it doesn't get expended as fast.

[LavaRed]

Is there any magic to wet suppressors? Is it really as simple as adding a few cc's of water to a K baffle design?

Yes there is some magic to a designed wet suppressor. Just adding water helps a suppressor perform better but doesn't make it a wet suppressor.

Most designed wet suppressors have some cavities that hold the liquid so it doesn't get expended as fast.

Or pulled back into the barrel chamber and blown into one's face. I've had that happen and overcome it.

A good wet suppressor should retain moisture for at least 3 or 4 magazines when fired, and up to a week when left in storage. At the same time it should be able to drain most of the water in less than 6 seconds, according to some military standards. Designing for both is quite the challenge.

[Bendersquint]

At the same time it should be able to drain most of the water in less than 6 seconds, according to some military standards.

Got a link for this Lava? I see it posted often yet I have never seen a military requirement that stated that.

[LavaRed]

At the same time it should be able to drain most of the water in less than 6 seconds, according to some military standards.

Got a link for this Lava? I see it posted often yet I have never seen a military requirement that stated that.

Nope, I actually read it on here and have been using it as a requirement in my designs since then. But now that you mention it I've never seen a source for it.