7.62 Tokarev Subsonics?


#1

Can anyone provide any info on the cartridges that might be used in these pistols? Assuming the men are Afghan Muj, I would further assume the pistol is Soviet.


#2

Jon, Judging from pictures I have seen from Darra, the TT-33 is a popular subject there. These could be local manufacture from Darra in Pakistan. Or, they could also be Chinese. Some Chinese stuff has showed up in Afghanistan, I know, although it doesn’t seem to be as much as one might expect. Wish the pictures showed the insignia on the grip. Then, we might know.

Of course, China has a subsonic 7.62 x 25 as you well know, but I don’t know that it was ever meant or used in a T-54 (Chicom version TT-33). It was really meant for an SMG.

John Moss


#3

True, we did fund the import of lots of Chinese hardware into Pakistan and Afghanistan. As you mentioned, the known PRC subsonic Tokarev round is for SMG use, and is much too long to fit into the TT mag and frame.


#4

Could it be single-loaded?

AKMS


#5

I just had some discussion with a person who has one of these devices and the matched TT pistol. He informed me that there are no special cartridges for it, but that the barrel is only rifled for the first half of its length, and that that modification slows the projectile down to an appropriate speed. I am not an Interior Ballistics Engineer, so it sounds good to me. If true, it answers a big question for me…Why are there TT “silencers”, but no known or documented TT subsonic cartridges?
Any thoughts?


#6

It’s a bit of a weird combination really. The 7.63 Mauser / 7.62 tokarev’s best property is the high muzzle velocity. If you take that away by reducing the charge and adding a silencer, you are creating an overcomplicated .32 acp. Might as well use a pocket pistol instead. Same results with less complicated work.


#7

True, but for a military application you might want to keep the weapon and its supply as common as possible to standard equipment.


#8

Supposition only - There probably would have not a great demand for subsonic loads, and such quantities as were needed could probably have been produced by handloading means, and may have been otherwise unmarked, except possibly by packaging. Or, maybe the partially bored-out barrel (in effect a short barrel) might have given the same ballistic results with a standard round. I’d think the rifled portion would have to be very short in this case.

One possible advantage of using a low impulse load in the TT-33 is that it might be desirable to not function the action, thereby not resulting in the clatter of the moving slide. If so, the pistol would be essentially a single shot, OK in an assassination scenario. Why not use a .32 or .380? I have no idea.


#9

My silenced 25 used custom loaded ammunition for just that reason. It was a magazine feed single shot. The slide had to be pulled by hand. Getting a shell with adequate range which would not work the slide was a bit of a feat.


#10

Hello CSAEOD,

Your gun working not semi auto is due to the fact your suppressor is of very bad quality and therefore needs a reduced load.

Indeed if you use 25 acp ctges with a normal load there is absolutely no reason your gun (except if it has a default) doesn’t recycle properly.
But due to the poor performance of your suppressor it will make too much noise despite the fact a regular load 25 acp is subsonic.

Using underloaded ctges (or using ported barrel) is a way to reduce the speed of the bullet and therefore the noise;
But what you win on one side (reducing noise) you loose it on the other side (less momentum, therefore less efficiency on the target.

People still use ported barrels when they want to use regular supersonic ammo .
This is the only time where a ported barrel could be allowed;
Same about underloaded ammo.
In all the other cases (using subsonic ammo) the suppressor is of bad quality if it needs that.

About the friend who says the reduced 30 tokarev load is as good as a 32 acp load it depends of the weight of the two bullets.
Once you have a subsonic load (just above the sonic speed) the effect depends on the weight of the bullet.
More heavy it is better is the momentum (p = m v).
Because you are working with a constant speed (v = 320 m/s) and this for any caliber (from 22 to .50) you see at once the best is achived with the heaviest ball.

Old designs (sten for example) used ported barrel for two reasons :
First you can use regular ammo you find on the field
Second the silencers were not as good as they are today (the mean reason being they were not chemically active, and this specially true about handguns)

You can argue ported barrels are still used today (MP5 for exemple).
Yes, but people using it complain about the inefficiency which is normal due to the loss in velocity.

The first guy who developped chimically suppressors in the US was Mickey Finn ( he died one or two years ago).
All the designs you find nowadays are copies of his idea, with more or less (!!) improvements.
The trick for a suppressor being to reduce the noise, therefore the exit pressure, therfore the temperature, you have only a few ways to do that: either by mechanic action (too complicated), either by slowing the gazes (too big), either by making the different waves collapsing (the most common but needs a lot of volume), either by chemical transformation (the best thing because of the smallest volume).

here are the dimensions for very good chemically suppressors used on handguns: (diameter x length)
22 lr : 1 x 3.2
32 ACP: 1 x 4.5
9 mm : 1 x 5.5
45 ACP : 1.25 x 5.5
These allow you to shoot two magazines without reloading the can and give you a sound signature less than the impact on a soft target. (lower than that would be stupid)
And the diameter of these cans allow you to keep the original sight.
I can add that the flight of the bullet is absolutely not altered.
As you can read I am talking about cans giving you a very very low sound signature, therefore real silencers.

I am not talking about the second kind of suppressors which are designed not to reduce dramatically the sound because of covert operation for example, but just to reduce the sound for the confort (physically or psychologic) of the shooter (police team obliged to shoot 223 in a building during an assault for example).

JP


#11

The design was with purpose to reduce total noise. Autoloading was not wanted. The cartridges were special loads with special bullets.


#12

Something new to me. I have not heard of a sound suppressor that performs through chemical transformation, but I have seen those that use water, grease, even personal lubricants, etc. as a gas coolant. How does the chemical transformation work?


#13

Something new to me. I have not heard of a sound suppressor that performs through chemical transformation, but I have seen those that use water, grease, even personal lubricants, etc. as a gas coolant. How does the chemical transformation work?[/quote]

This is what I call chemical (or if you prefer physic)

For a physical substance you need to bring energy to transform it from solid (ice for example) to liquid (water) then to vapor.

the energy in the can is given by the hot gazes.

Delivering energy to change the state of the substance in the can means the temperature is decreasing and by consequence the pressure.

Sound been given by the difference of pressure between the ambiant air and the air exhausting the can, lower is the pressure difference lower is the noise.

At the beginning they used water.
this is one of the physical substance which has the best caloric power and the one giving you the best noise suppression.
(This is what you call a coolant. No as many people because it is water but because it drops the temperature)

But as you know the water inside the can will evaporate very quickly and after 5 or six shots the amount of water still remaining in the can will be too small to give you a good noise suppression.

After they started to use grease (either as paste or as oil) just put on the internal walls of the silencer or kept held buy either mesh or by a special chemical substance.
In this case you need to choose a grease with an high flash point, in order of not to be destroyed by the high temperature of the hot gazes.
Lithium grease is one of the best one.

As ever physics is always a compromise.
With grease you can shoot more rounds without refilling the silencer but the noise suppression is less than with pure water.

As you said everybody has his own recipe and keep it secret !
About me I use solid lithium grease for common use.

If one day special use is needed (need to shoot more than 2 magazines of 15 9 para rounds for example without reloading the can) I put the grease not directly on the internal walls of the silencer but through a chemical (not physical) coumpound acting as honey comb.

JP


#14

I believe we are talking about the same thing. The whole idea of a sound suppressor (or sllencer, if you prefer) is to retard the release of gas resulting from the burning of propellant. The most efficient way to do this is to cool the gas, thereby greatly reducing its volume. The evaporation of water (which is a physical change rather than a chemical change) results in the absorption of heat from its environment (heat of vaporization), and water has a very high heat of vaporization (540 calories/gram). Although greases and oils can also vaporize to some extent, their heats of vaporization are much lower, and the phase change occurs at a much higher temperature. Therefore the evaporative gas cooling effect is far less than if water were used.

It’s been some time since I had anything to do with suppressor technology, but I think that the most modern suppressor designs no longer rely upon gas cooling using water, oils, etc., although it is likely that suppressors using such coolants are, and will continue to be, in use. I would think that the most effective suppressor would be designed around a baffled container filled with a very porous and permeable but absorbent (hydrophylic) material which was water-wet (or possibly wetted by a gel containing a high water content, which would stay in place better). But it would likely require re-wetting after just a few shots. But then, one must also worry about suppression effectiveness at sub-freezing temperatures.


#15

yes Denisk we are talking about the same thing.

What you call “retard the release of gaz” I call it"drop the pressure"
(If you just delay the gas keeping them at the same temperature (or heat) it will have no effect)
what you call “heat of evaporation” i call it “calorific power”

And I said chemical instead of physical (as if it used only Carnot cycle to cool the gazes) because I said the “coolant” is kept in a chemical substance.

What you call hydrophylic material is what I call gelatine (in french) .
The gelatine can be more or less elaborated of course, its goal being to keep prisoner molecules of water like in an honey comb.

You can use porous cermic also. It works good. (this been a modern improvement on meshes impregnated with grease)

The only point where I disagree with you is when you say

" I think that the most modern suppressor designs no longer rely upon gas cooling using water, etc., but would be designed around a baffled container filled with a very porous and permeable but absorbent (hydrophylic) material which was water-wet "

The fact to use an hydrophylic material is just an improvement.
The principe is always the same : cooling the gas by using Carnot cycle.

Now regarding how many shots without refilling is a question of design of the internal baffles.

Do not base your experience upon US silencers, I knew them pretty well (AWC (the first one with Mickey Finn), AWC (the new one), Ciener (no longer in business) , Knight Armements, Phil Dater company, and so on) and except a few designs they are pieces of crap : very expansive, poor mechanical alignement (very very often the bullet touches the inner part of the silencer), bad noise suppression and so on

I don’t say that from litterature but because I tested them (velocity test, noise suppression test, accuracy test and examination of the bullets after shooting) during more than ten years.

Due to the fact you must pay a special tax and make all the special paper work to own one, silencers are mythic in the US.
Therefore the US companies sell you for example for more than 300 the same can you can have for 20 in France where they were legal without any paper till 2 months ago (now you must have a license fot the ones used on handguns)
And can you have for 20 ?? Nothing very good ! Imagine now a good design costing 400 in France. What would be the price in the US ?? Too high to be sold.

JP


#16

To clarify, I did not make the statement you quoted: " I think that the most modern suppressor designs no longer rely upon gas cooling using water, etc., but would be designed around a baffled container filled with a very porous and permeable but absorbent (hydrophylic) material which was water-wet. " You have combined two separate and unrelated statements I made.

Retardation of gasses means slowing down the velocity of gas release. At the muzzle, some of the escaping gasses move at a velocity greater than the bullet (usually assumed to be 1.5 to 2 times the bullet MV), thereby producing a supersonic pressure wave that results in sound. If the gas release velocity into the atmosphere can be greatly decreased, then so is the pressure wave. It is done in a suppressor by cooling the gasses. How the cooling is achieved can differ, as it can be either by adiabatic expansion of the gasses through baffles and ports (a part of the Carnot cycle, which is how a refrigerator works), or by vaporization of another medium such as water by the heat contained in the gasses - or both.


#17

[color=#0000FF]hello Dennisk,

About your statement , it was :
I think that the most modern suppressor designs no longer rely upon gas cooling using water,oils, etc., although it is likely that suppressors using such coolants are, and will continue to be, in use I would think that the most effective suppressorwould be designed around a baffled container filled with a very porous and permeable but absorbent (hydrophylic) material which was water-wet.
I don’t see in which way I have altered your statement by cutting the underlined words.
This is for sure due to my bad english language, sorry.[/color]

Retardation of gasses means slowing down the velocity of gas release.
[color=#0000FF] In physics for me retardation (delay) is the fact that something happens a little bite further than the initial phenomenum, without changing the characteristics of the initial phenomenum.
If there are changes it is not a delay.
therfore the term “delaying gas” is inadequate.[/color]

At the muzzle, some of the escaping gasses move at a velocity greater than the bullet (usually assumed to be 1.5 to 2 times the bullet MV), thereby producing a supersonic pressure wave that results in sound.

[color=#0000FF]you don’t need to have a supersonic pressure to produce a sound.
Sound is made by the difference of pressure in comparaison to the ambiant pressure and this for as low as a 1/100000 difference[/color]

If the gas release velocity into the atmosphere can be greatly decreased, then so is the pressure wave.
[color=#0000FF]Pressure for a gas is related to its temperature.
therfore decreasing the velocity, decreasing the temperature, decreasing the pressure it the same thing[/color]

It is done in a suppressor by cooling the gasses. How the cooling is achieved can differ, as it can be either by adiabatic expansion of the gasses through baffles and ports (a part of the Carnot cycle, which is how a refrigerator works),
[color=#0040FF]You don’t have an adiabatic transformation in a silencer.
By definition adiabatic means there is not heat transfert between the gas and the outside.
This hot gas touches the cold walls of the silencers and because of that there is an heat transfert [/color]
or by vaporization of another medium such as water by the heat contained in the gasses - or both.
[color=#0040FF]Furthermore all these terms (and the associated equations) are for what we call steady state domain.
Now, in the real experience, we are in what we call the impulse domain.
Equations are a lot more complicated.
If you add the fact that we don’t have pure gas, that particles of powder are still present and burnig, and so on , it becomes an headache[/color][/quote]

[color=#0040FF]All of that you know perfectly, it is just a question of language.
And at the end only the results count.
JP[/color]


#18

Do any of you have any further information specific to the 7.62x25 Tokarev cartridge/silencer question?


#19

Just as examples of what can be done (but not with the Tokarev, necessarily), have you looked for info on the Jones Micro- and Mini-Whispers? These are based on the .30 Mauser and 7.62x25mm cases and come in sub- and supersonic versions. Unfortunately, they were designed for the T/C Contender, so the COL is too long for the Tokarev.


#20

Jon, here is a picture of a subsonic loading of the 7.62 x 25 next to a 7.62 x 39 US. I have no further information, but maybe some of the Russian contributors can help (is this related to the suppressed Tokarev or the 7.62 x 28 RG037 ?).