Improvement suggestions for this monocore?

[kokopelli]

...22lr, the monocore is 5" long by 1" diameter. One straight-through hole, .274" and is not hearing safe at all, unless it is dripping wet and only with subsonics...

Thanks for any suggestions!



Should I drill some smaller holes on the outsides of the baffle areas to create more turbulence?

[Capt. Link.]

You can't muffle the super sonic boom of a bullet as it happens out side of the suppressor body.Sub-sonic projectiles can be very quiet but it depends on host weapon.Some designs work better on rifles than pistols and visa versa.FRP can be very loud on pistol suppressors.A little lite oil or water will help.If this suppressor is very loud dry and quiet wet the design is poor .If you live in the US you are prohibited from doing any modifications to this suppressor.If it is a F1 build you may only remove metal and not add any to modify it.Who built it and what is the host weapon.
-CL

[Bendersquint]

You can't muffle the super sonic boom of a bullet as it happens out side of the suppressor body.Sub-sonic projectiles can be very quiet but it depends on host weapon.Some designs work better on rifles than pistols and visa versa.FRP can be very loud on pistol suppressors.A little lite oil or water will help.If this suppressor is very loud dry and quiet wet the design is poor .If you live in the US you are prohibited from doing any modifications to this suppressor.If it is a F1 build you may only remove metal and not add any to modify it.Who built it and what is the host weapon.
-CL

The good Cpt is right, where you are in the US and that is a Thompson Machine core only an 07/02 licensee can modify it.

[a_canadian]

Am I seeing this wrongly, or does this core mount backwards on the host? Looks like the knurled end is the part which threads onto the host gun, right? But if that's the case, why are the points of the V baffles facing away from the muzzle? I'd expect this to fail utterly as a suppressor. Perhaps a factory error, the part having been made incorrectly yet somehow sold?

[doubloon]

Looks backwards to me too but I've been drinking and I've never made a suppressor.

[a_canadian]

Perhaps a picture showing which end threads onto the barrel would clear this up. I looked at a few other Thompson monocores and find them a bit confusing... so maybe in this one the points of the V baffles face the muzzle, as they should.

[kokopelli]

Sorry for the confusion:

All laws followed- local sot manufacturer in hand...

The knurled end pictured on the left in top picture is the exit hole, V points are toward the muzzle.

The recommendation was to install a wipe at the exit (he doesn't make many cans, hence my question here).

[doubloon]

A wipe will likely kill any hope of accuracy.

It's difficult to gauge from the picture but what is the size of the bore hole?

If it's 1" in diameter that exit hole looks like it might be nearly 1/3"

Do you have access to the drawings from which the suppressor was made or at least a list of the dimensions on which everything was cut?

[kokopelli]

A wipe will likely kill any hope of accuracy.

It's difficult to gauge from the picture but what is the size of the bore hole?

If it's 1" in diameter that exit hole looks like it might be nearly 1/3"

Do you have access to the drawings from which the suppressor was made or at least a list of the dimensions on which everything was cut?

no access to any info on it; it was a one-off machining for the tube...

exit hole is 0.275", entrance holes is the same, and I can't measure the interior holes diameters.

Here are some more pics:

How the core and end are laid out:
Entrance (screw on) on the left, exit on the right-


Muzzle threads and core entrance hole:


Exit for bullet end, knurled:


Army issue m16 .22 cleaning rod through it:



Thanks for any ideas!

(Also, the manufacturer {I don't want to mention here} took care of me by replacing the suppressor with a new, better model, but I would like to salvage this one to use if at all possible since I do have a stamp on it.)

[doubloon]

0.275 is not as bad as I thought from eyeballing the pictures, sorry I missed it earlier when you said 0.274.

What host and what ammo are you shooting?

[sub-sonic]

have him make another end cap and chuck that monocore away and pack the tube with freeze plugs or quiet washers or cones and go with a .250 hole

[a_canadian]

Well that would be silly. If you're chucking the monocore, why fill the tube with crappy washers? K baffles well designed and executed will deliver much more efficient suppression than any monocore, and certainly better than any freeze plugs.

[sub-sonic]

Well that would be silly. If you're chucking the monocore, why fill the tube with crappy washers? K baffles well designed and executed will deliver much more efficient suppression than any monocore, and certainly better than any freeze plugs.

flat washers spaced 3/8" apart would do far better than that monocore.

[a_canadian]

Sure. But why waste the time and money recoring with washers? If you're going to the trouble anyway, why not make it a good K baffle can which actually makes shooting quiet and enjoyable?

[Joker31D]

I agree it looks like its backwards. It looks like an old design and backwards, I think the newer style ones use alternating asymmetric baffles that are optimized for surface area and for wave cancelling ability. That looks like what most people would make if they didn't understand waveform propagation, (Engineering courses made that sound smarter than it was) The sound is just a wave, like water, your trying to keep it from reaching shore by sending waves the other way. I haven't built a suppressor but thousands of Sound Enclosures for people, most custom, over 25 years. (Home theater and commercial theater sound systems are a hobby) I know about sound cancellation, that thing doesn't seem like it would.

The Sparrow is a good example of a 4th Order Band-pass Enclosure, it lowers the Frequency of the wave by making the path to your ears longer by bouncing it off of other surfaces. That lowers the frequency of the sound by reverberating off the walls and thats why the sound is lower toned and more pleasing to the ear. it lowers things a few octaves on the whole scale. Some of the sound is cancelled because the wave bounces back on itself and a force in one direction met by an equal force is cancelled. No right angles because its too rough on the walls of the can and woundnt last as long so a compromise is made for durability by slanting them and adding surface area. That slant you have seems to be facing the wrong way and actually raises the sound, most likely sounding tinny and high pitched. Like a coffee can.



But I could be wrong, its just the way I was taught.

[a_canadian]

The wrong way around thing has already been dealt with. It's not. The original poster spelled out with more photos and an explanation that the points of the V baffles face the gun's muzzle, the correct direction.

[kokopelli]

here is my unique art skill to help out- bullet travel goes in arrow direction

[a_canadian]

You know how the little cross jet scoops get milled into one edge of the entry point on cones or K baffles? Perhaps you could try that on these V baffles. A ball burr in a Dremel or something, carefully carving down on one edge of the V point to maybe half thickness or a bit deeper. Then on the opposite side on the next baffle, etc. Get some flow zig-zagging down the stack. Chaos beats symmetry in suppression efficiency.

[sickasssig]

I have a simple monocore with 1 1/4 holes drilled down the stack and it sounds great simple and easy build maybe your expectations we're to high and not met would add pic but not exactly sure how to do so

[Elkins45]

You know how the little cross jet scoops get milled into one edge of the entry point on cones or K baffles? Perhaps you could try that on these V baffles. A ball burr in a Dremel or something, carefully carving down on one edge of the V point to maybe half thickness or a bit deeper. Then on the opposite side on the next baffle, etc. Get some flow zig-zagging down the stack. Chaos beats symmetry in suppression efficiency.

That's exactly what I was thinking.

[kokopelli]

thanks guys- I got a couple of similar, very good suggestions and directions. I also found another 07/02 to do the work, instead of the guy who wanted to glue a wipe on the end

[Capt. Link.]

thanks guys- I got a couple of similar, very good suggestions and directions. I also found another 07/02 to do the work, instead of the guy who wanted to glue a wipe on the end

Wipes have there place but not so much on sporting weapons as they degrade accuracy. I don't know how they metered but a old Hush Puppy with fresh wipes is very quiet small and light for its age.The accuracy is (one goose of angle) inside 25yds or better.