How to make sumo quieter

[Jubei]

So I bought the Donny fl sumo , look great but not as quite as standard hw mod , anyone ever added anything to make it quieter

[angrybear]

I believe you can buy extra sections,
best way to make them quiet is replace them with something that works.

[Trumpetier]

They do appear to be all show and no go from what I've read about them. Stick with a HW mod.

[gc93]

I believe you can buy extra sections,
best way to make them quiet is replace them with something that works.

the pen is mightier than the sword comes to mind, how to kick a mans teeth in with no boots on !

[joffy]

Feed him plenty of sushi and rice

[Racing]

Ok.
I´ll bite, and will bore you guys stiff for a minute or two.

By now i´ve been at this for a while (read - years) building my own suppressors and have learned a thing or two on the subject, i´ll tell you that much.
Today there´s like a zillion different brands to pick from, so HOW do i get/pick one that´s right for me - as far as an effective moderator.

1/ Power goal.
To muffle the tone of a 12fpe gun is NOT the same thing as doing it to a 120fpe unit - assuming both are pcp´s. In a few words though what it comes down to is baffle through hole diameter and volume (of suppressor).
I appreciate that there´s like kilometers worth of writing on which baffle setup and methodology is top dog, i really do, but the honest to god truth of the matter is that it ALL takes a back seat to baffle through hole diameter.
No matter if for a 12fpe or 120fpe unit. Actually, as you´ll read soon enough, for 5900fpe units too.
That being said then, for your guys in 12fpe land it thus just stands to reason to look domestic. Why? Simple, the 12fpe market is HUGE in Britain compared to the FAC crowd and as such of course most moderators cater to that.
Compared to the DFL mentioned above.

2/ A pcp is not a powder burner.
Around here it´s all the rage to use suppressor units intended for a 17HMR or 22lr... or 22Mag.. yadda yadda yadda. You get the idea.
The issue is that such a device, intended for a powder burner, WILL work. Just very far from optimal, by a landslide. Reason for this is simple. The two are about as apart as can get on their pressure curves.
This is also why we see gains (as in reduced amplitude vs frequenzy) as a moderator body for a pcp increases to a MUCH greater extent than for the equivalent powder gun.

3/ SO much is lost due this Hollywood fallacy that suppressors are something "you throw on there", and preferably in a jiffy.
Look...

As noted. Suppressor efficiency is to a downright mind boggling degree about through holes. Period.
Those that believe otherwise...conduct and experiment for me will ya. Take a regular Hatsan QE anything. The innards of it is per moderator standards an absolute joke, at that a 22cal such normally has an end cap opening on like 10-11mm.
Now.
ALL you do is either turn one yourself or have someone with access to a lathe do so, see what you do is turn an insert to fit the stock opening on the end cap on said Hatsan QE setup. Like a press fit bung out of aluminium that sports a collar to make it stay put and then on an opening on 7mm for a 22 gun or 6mm for a 177 one.
Notice that the measurements given are FAR from "tight" vs caliber.
But.
Please do so and report back on your findings on what happens to amplitude (volume) as well as tone (frequenzy).
The net result then being from bringing ONE through hole diameter down. ONE, and i bet your jaws will drop like a ton of bricks.
Now.
Please appreciate that most high performance moderators work on 4..5..or even 6 chambers. Do the math.



(Prototype suppressor for 110fpe pcp)

What i´m saying is that this soon becomes a game of point of diminishing returns and as such.. as you creep up on closer and closer tolerance vs caliber.. it gets more and more important that linearity is absolute between the barrel (or diffusor where applicable) and the moderator through holes.
Me i more often than not these days end up on caliber + 0,1" for the radii.

The easiest way to solve that dilemma at hand is on a lathe using a dial indicator, and if you like me like your pcp´s WAY BEYOND "backyard friendly" this is really the only viable option there is.

Most of us have at least heard of baffle whip.
The effect where linearity per above isn´t adhered to, where the pill touches on the through holes on the baffles or the end cap on its way out..and accuracy goes down the toilet in a landslide.

First up.
Linearity between the suppressor and the barrel is NOT handled by their threads. The threads are there to invoke torque between the two as you tighten the suppressor down.
What DOES handle linearity is the two faces that mate. On the barrel and the rear of the moderator both.

So.
As ppl in general have effed this up beyond belief the industry has just come to claim that; "go one or two sizes bigger than your caliber". Well, if there EVER was a bullshit statement it´s that one.
As linearity is measured in hundreds of a millimeter in this case (or thousands of an inch if you wish) you soon enough realize that the chances that you torq that moderator down in EXACTLY the same spot with the EXACT same force time and again... not happening. That simple.
Thus, the industry goes.. "go one or two sizes bigger than your caliber", and here´s the kicker to that!
There´s STILL those that get in trouble even doing so!



Look.
If you´re serious about this take to heart that you can not beat the inherent physics of this. Plain and simple.
Sure.
Muffling a 12fpe unit isn´t all that. No offense, but it really is not. However, if you REALLY want to go stealth there one way to do this and one way ONLY.
Keep through hole diameter close to caliber, index the moderator install on a lathe using a dial indicator. Period.

Yes.
All to aware of so called K series baffles and a gazillion spawns on that and what have you. Doesn´t matter. It ALL still takes a MASSIVE rear seat to through hole diameter, end of story.

In turn.
You guys on here shoot 12fpe for the most part. Contrast time. This little journey of mine started out rather low key and laid back a number of yrs back by now and of course there´s been a *rapload of lessons learned along the way. That was staying subsonic. However...
That in turn lead me to look into my powder burners, which is an ENTIRELY different story all together, especially so seeing they´re supersonic.

All to aware this part of the forum is the 12fpe one i´ll just dive in, as it IS on mark to prove a point.
Cause see, one thing (as often) sure handed the other.



So i´ve got this Sauer STR in 6.5*55 Swede mainly intended for PRS. Supersonic if ever, while be that as it may the suppressor on there is so effective at what it does that you can fire 10 No of 5 shot series without wearing any hearing protection what so ever. Kind of surreal, cause the gun doesn´t really go off that hard but that´s followed by a whistle.. and then a klang 10-20 times louder vs the actual firing as the pill hits the steel 100 meters downrange. Please be adviced that the pills used exit just short of or on 3000fps.




Well. This of course made me grab the bull by the horns for real for my RPR in 338 Lapua Magnum, which i mainly use for ELR. Now.. that´s a LOT of gas n heat..
What i came to dwell on was that if a simple so called reflex chamber suppressor is as effective as it is, what about a DUAL reflex chamber one?
Bingo.
Albeit the stock muzzle brake on the RPR is ample, that dual reflex jobbie cuts recoil with an easy additional 30-35% somewhere and cuts the report of the unit down you won´t believe.

The flipside to both of them is... heat, and i´m knee deep in trying to come to terms with that current.
Added a mirage band to the Sauer as late as today (already wears a "sock" on the actual can).
In turn going to modify a small hand held fan that you charge via a regular USB port to flow cold air through a dummy casing for each caliber, to hand airflow through the barrel between rounds.

And although these two (well three actually) archetype suppressors might come off as being completely different entities, and they are to a degree, they all work by slowing gas down and in turn level pressure out. Kinetic energy and heat converted into pressure.
No matter if a suppressor for a 12fpe unit or one for a 5900fpe long haul sniper job.

Summary?
STOP believing that you´ll reach "dead quiet" levels as long as you insist on bolting said moderator on n off like your changing your underwear. It simply does not work that way.
If you´re serious about going down this road, to make the gun of yours insanely quiet, the moderator is to be installed STIFF once and for all (for real!) then to be dialed in on a lathe.... and then left well enough alone.
At that point, feel free to just "line" the through holes on the baffles n endcap on your current moderator of choice using small inserts you or a friend of yours turn out of regular dirt cheap aluminium. No point in reinventing the wheel, i guarantee.

Also be aware that this is one instance where the 177 boys actually have the upper hand.
Why?
Simple, a 177 presents way less cross sectional area vs say a 25cal and thus there´s less area for the air (read - noise) to pass the pill or even its rear stream.
Just pure logic if you think about it.