Was there a subsonic 7.65 (.32 ACP) made during WWII


#1

Was there a subsonic 7.65 (.32 ACP) produced during WWII by the Germans and/or Czech? for use in the CZ-27 equiped with a silencer?

I am very interested in any line drawings or cutaway pictures of the silencer. I have good pictures of the exterior but I need internal layout and connector details.

Any help would be appreciated.


#2

Gene-most .32 auto ball rounds are subsonic, so there was little need to create a special round for silencers, including the one for the CZ Vz 27. However, the Germans did load a round many call silencer rounds; I call them clandestine rounds, made to reduce evidence of responsibility when a fired case was found at the scene of a shooting. The headstamp is similar to the later 9mm Nahpatrone, with nothing but a “X” for the headstamp. They are loaded in a steel case. Again, since the standard round is subsonic, I think this is just an instance of a “anonymous” headstamp, not a special loading per se. The Woodin collection has, as I recall, a Geco round with an all green case like the earlier Polte nahpatronen in 9mm and 7.9 x 57. I don’t know the particulars of it - brass or steel case, etc. nor the loading. Since it has a standard headstamp, the green case should indicate a special loading, but again, as a special loading really was not especially necessary, I cannot fathom the reason behind this cartridge.

I believe the “X” headstamped 7.65 Browning rounds were probably made by Geco, although they also could have been made by DWM Berlin-Borsigwalde. Steel cased, normally headstamped rounds from DWM and Geco in this caliber are very similar in characteristics, including the red-colored seals used. I don’t have any documentation on who actually made them, either way.


#3

Thanks John. I believe most European 7.65mm is loaded a bit hotter than US made rounds. I see references showing 1140fps to 1250 fps (US loadings being 925fps). The speed of sound is usually around 1080. Colder days may be somewhat lower. A .380 is usually subsonic but I think most European 7.65 would break the sound barrier.

The info on the “x” marked cartridges and green cased rounds was exactly what I needed! Thank you very much for that information. Many silencer designs of the WWII era used rubber plugs or “wipes” to retain the gas in the silencer as the bullet exited. This should have been enough to slow down a marginal round like the 7.65 to subsonic velocities. So if the Czech CZ-27 silencer used such a design, I agree with you John, no special round should need to be loaded.

If the Czechs designed the silencer similar to the earlier Maxim patents, no wipes were used (only carfully designed baffles). At that point a slower loading was required. Especially if shooting in colder climates. Thus I would really like to see a cross section drawing of the CZ-27 silencer.

Thanks again for your great information John.


#4
  1. The European 32 ACP and 25 ACP have very often a bullet diameter which is DIFFERENT of the US one.
    It is a nightmare when you reload if you mix cases and bullets or Us and European origin.
    (the french 25 or 32 bullets fall for example into an US case)
  2. And you cannot chamber for example a ctge made with a NEW MADE Italian bullet (which is US standard) in an old German of French gun if you have reloaded it keeping the same length as an French ctge for example.
  3. Till recently (30 years ago) FRENCH, GERMAN, ITALIAN, aso were subsonic

jp


#5

Gene - I have checked many current catalogs this morning for the major current manufacturers of .32 auto (7.65mm Browning) and found the following listed muzzle velocities for that caliber:

SAAMI 900 FPS
Geco 1000 FPS
CBC 906 FPS
Hirtenberg 984 FPS
MFS 1017 FPS
Fiocchi 1000 FPS
PMC 900 FPS
S & B 1043 FPS
PPU 901 FPS

Many of these have admonitions that they are either instrumental velocities from pressure barrels, or that they are taken under ideal conditions and that they may vary due to altitude, barrel elngth, temperature, humidity, etc.

My personal opinion is that out of a normal .32 auto pistol barrel few would exceed 1000 FPS under field conditions.

The high end of velocities you mention are for special loadings such as the French THV, plastic training bullets, etc. or for weapons specifically adapted to the load, like the Skorpion SMG or the Frommer Pistol (“Frommer Ladung” - Frommer Loading).

Of course, velocities are also higher for the hollow point .32s, most of which have bullets in the 60-grain range. My comments are all based on the 71 to 73 grain FMJ bullet.

Most, not all, .32 auto pistols are straight blowback in operation. Load levels are very important. The case velocity (sometimes called “case thrust” or “timing”) is very important. If the case leaves the chamber before the bullet has left the barrel, the case head becomes unsupported although still under pressure and can badly bulge or even burst, causing possible injury and certain damage to the gun. this “timing” is very critical in blowbacks and they are not tolerant of a very large spread of pressures and velocities like some locked-breech pistols are.

I found that when I started loading 9mm Makarov, before any supply of ammunition was available. Fortunately, I stopped increasing the loads as soon as I got the pistol to function perfectly. I was using shortend 9mm Para cases (not all together satisfactory, by the way, for many reasons) and cast .380 bullets not resized. In the absence of molds or bullets of proper diameter I gave up on it, as the loads were accurate when the still-undersized bullets took the lands, but very wild when they did not.

Some blowback pistols designed for “hot” loads compensate for this by heavier recoil springs or heavy slides, like the Astra 400, the Campo Giro, or in the latter case, the MAB PA-15. (As I recall, the MAB is not pure blowback, having a slight rotation to the barrel, but I could be wrong about that. It is certainly not a fully locked breech in the sense of the Browning tilting barrels, Walther style prop locks, etc.). The best example of trying to overcome the unsupported case head problem in a blowback pistol is the 9mm FAR, which has the solid head of the case lengthened so that even if part of it has left the chamber, it will not expand. The FAR has been covered on this Forum as I recall.

The point is, MOST 7.65 Browning ammunition is, even today, subsonic and I agree with Jean-Pierre that older loads were almost all subsonic, except perhaps the Frommer loadings. Erlmeier and Brandt don’t show the 17mm case Frommer (same as .32 Auto) as a separate round, but even the short case (13mm) round shows a MV of 1115 fps. By the way, even though a European book, E&B shows the average MV of the .32 Auto round as 984 FPS.

I believe, again, that the “X” headstamp was much more a matter of concealment of the manufacturing source, in case a case was left behind at an assasination, than a matter of identifying a special load for silencers. I could be wrong, of course, in absence of documentation of these rounds. The boxes are of no help at all - of course being anonymous, purposefully, I’m sure, for the same reasons the cartridge was. Just my opinion but based on some study done when I acquired my first variation of the “X” headstamp on 7.65mm (32 auto) many years ago. My first ones - I had four rounds, came out of the magazine of a WWII bring-back Walther PPK - no silencer provision - that had been loaded since that time. I acquired them circa 1966. I unloaded the pistol myself. The other rounds were Geco steel-cased rounds.


#6

Your evidence is overwhelming. I am convinced. I apologize for being so slow. I am no novice to silencers nor ammunition but have always heard .32 was supersonic. Never believe what you hear and only half of what you see. I hope no hard feelings.

The reason for the inquiry is I am buying a WWII Czech CZ-27 with the extended barrel for use with a silencer. Recent books on Czech pistols have some information on the guns and pics of the silencer from the outside. Nothing showing internal views. I have since found a Frankford Arsenal report from the 1960’s on silencers showing cutaways of several WWII German silencers. I believe one is for the Cz-27 and mislabeled. Any European help would be appreciated. Since no special ammo was needed, that would prove to be an effective weapon in trained hands. Late war production in small numbers was probably a good thing for us.

Thanks John and Jean


#7

Gene - no reason at all for hard feelings, but appreciate your concern. Just a discussion of ammunition between two friends. Lord knows, I am probably wrong as often as I am right in such discussions. Hope to see you at St. Louis.


#8

German documents and silencer trial reports always mentioned about
a 7,65 Br. round with REDUCED powder charge. So there must be a
reason for that, may be a subsonic load wasnt enouth.


#9

That could be possible. I suppose the sound signature goes down as the velocity of the cartridge is reduced. I would have thought that they would have wanted to keep the diminutive 7.65mm Browning cartridge to as full a potential as possible, since it is a poor anti-personnel round to begin with. I suppose that wasn’t a factor in the way these silenced pistols would have been used though. I have never been privy to any of those reports on the .32. Wish I had them. In truth, the 7.65 Browning round shouldn’t need any reduction in velocity to work with a silencer, but then I suppose that would depend a bit on the efficiency of the silencer being used - some are better than others - and how much noise was deemed acceptable. The “X” headstamp made some sense, as it would conceal the manufacturing point of any ejected cases found at the scene of an assassination.

Interesting information though. thank you for posting it. It is the first I have ever heard of any documentation about reduced .32 loads for silencers.


#10

Knowing nothing about 7.65mm Browning cartridges will not prevent me from replying to this thread! From what I’ve read in this thread, it sounds like 7.65mmB ammo would be 900 - 1100 fps muzzle velocity, considering the variation encountered from bbl length, manufacturing variation (which is suprisingly large to me) and similar factors. I don’t know what the WWII era European 32 s were loaded to. I know from tests of 9x19mm NATO spec ammo from a number of countries I once watched, there was a suprising variation.

The speed of sound at 70F in dry air is 1130 fps, but drops to 1087 at 32F and to 1067 at 14F. so now we are down in the range of muzzle velocity that may be seen on some of today’s (S&B) ammo.

If a bullet is traveling at supersonic speeds when it leaves the muzzle of the silencer the associated shockwave will create a sharp crack sound which will reflect off of hard objects nearby and go in all directions. This crack is one part of the sound of a gun firing, the other parts are associated with the actual firing of the cartridge (gas expansion out of the barrel, etc.).

The supersonic crack is also effected by wind (actually wind shear) which makes the whole issue of effective and consistant silencer operation even more complicated and uncertain.

If I wanted 7.65mm ammunition that I was positive would work in a silencer EVERY TIME IT WAS FIRED in all kinds of conditions, including extreme cold, I would insist on a reduced charge loading that I knew, at the 99.999% probability would be subsonic out of the silencer. I wouldn’t trust normal 7.65mm ball ammunition to meet this performance.

I’m not at all surprised that the Germans in WW II procured a reduced powder charge 7.65mm Browning load.

Just one person’s opinion.


#11

Lew - your argument makes good sense but ignores the ability of the ammunition to function the weapons used. A reduced load could limit the usefulness of the ammunition to specially-tuned pistols re-engineered to shoot that ammunition reliably, depending on the load. The last thing a person needs when in the type of situation in which these weapons would be used would be malfunctions of the pistol.

Still, it is possible, of course, that such pistols were specially tuned. A primary silenced pistol used by the Axis was the CZ 27, in a special model intended for silencer-use. It would be nice to measure the strnegth of the recoil spring and the hammer springs in one of these compared to a normal pistol.

Another factor, of course, is how much the load was reduced. There is, naturally, a functioning tolerance level in any pistol, including blowbacks, to account for small differences in the operating forces generated by different makes of ammunition. Slight decreases in powder charges probably would NOT effect functioning of blow-back pistols. I have loaded for several different blow-back operated pistols and found them to be fairly tolerant of loads on the light side, although not on the heavy side due to case-head expansion from residual pressure as the empty case is leaving the chamber.
timing on a blow-back pistol is rather important.

Interestingly, one of my two variations of the “X” headstamp 7.65 Browning cartridge came from the magazine of a Walther PPK, standard pistol not adapted to silencer-use, brought back from WWII. It had been in the magazine, along with three other “X” rounds and two rounds of Geco steel-cased rounds, until a few days before I acquired the rounds. There was another Geco in the chamber, which had not been removed. The gun was brought into our store by a vet, who was told by a friend that “there is a guy at the Gun Exchange that would love to look at the ammo in your gun.” He took it out of the clip at home to see what his friend was talking about, and they both thought the “X” was probably special. He reloaded the clip, put it in the gun, and brought it into the store, handing it over to me totally loaded and ready to go. Of course, a guy who walked around Europe for a year with a loaded weapon, and handn’t handled guns since, would feel this is quite natural, I guess. He gave me all but one each of the two headstamps that were in the gun. Had I thought about this discussion then, I would have disassembled one of the Geco rounds and one of the “X” headstamped rounds, but I am not, at this stage, going to take apart either of the “X” rounds in my collection for weighing pwoder charges, etc. However, while it really proves nothing, I did weigh my two “X” rounds against two steel-cased Geco rounds (due to cartridge characteristics,it is my belief that Geco made the X rounds, not DWM Berlin-Borsignwalde, or the DWM-controlled FN Liege plant, both of whom made steel cased 7.65 Browning), with the following results:

“X” Number 1: 115.1 grains 7.46 Grams
"X" Number 2: 113.4 grains 7.35 grams
"Geco" Number 1: 111.6 grains 7.23 grams
"Geco" Number 2: 115.0 grains 7.45 grams

If everything was equal - type of powder, amount of lacquer in the seals and on the cases, etc., I would have to say the powder charges are about the same in all four rounds. Regardless, we cannot know this, so as I say, while interesting, the total weight of these four cartridges actually proves nothing. The only round dramatically lighter is Geco Number 1, not either of the “X” rounds. Certainly, the bullets in the “X” headstamped 7.65s are not heavier than the norm, as are the projectiles in the 9mm Para “X” rounds, another way to reduce velocity.

The defining information about the use of lighter charges is the German Documentation mentioned by Genkideskan. Anything else, including my own opinions, are purely speculation. I would love to see those documents, especially since I know of a Geco-headstamped cartridge with the case lacquered completely green and I have an FN steel-cased 7.65 Browning with the case entirely lacquered green, as in the famous 7.9 x 57mm and 9mm Green-case “Nahpatrone” cartridges.


#12

John I cant see you suffering. The documents are copys from a sort of blueprint and in very bad nearly black quality. I try to scan it but you cant read anything than. So I will write the text here.

[b]Arbeitsnachrichten Kummersdorf 19.11.1943

Ermittlung der Ladung f


#13

John, Thanks for the excellent insights. Of course you are correct that the reduced charge load would still have to function the pistol EVERY TIME! Given that SAAMI is down around 900fps which I have to assume is sufficient to function blowback pistols consistently, it appeared to me that gun function would not be a problem. From what I’ve seen, German WW II ammunition had much more consistent performance than current commercial and military pistol ammunition. Given this ability to produce ammunition with very consistant performance, and the ability of blowback pistols to tolerate low loads, a target muzzle velocity of 850-875 would provide operation in very cold weather and be unlikely to create a problem for a wide range of autopistols without modification. If you wanted to improve the pistol functional reliability with light loads, that could likely be achieved by simply selecting the lighter weight slides from normal production variations. Us collectors would never notice the difference in the pistols.

Your cartridge weight comparisons are interesting, and confirm my measurements in 9mmP that the bullet weight variations are more than sufficient to obscure variations in the powder load! You can’t identify a proof load by weighing the loaded round!!!

I had not heard of the green case 7.65mmB rounds—lovely! They are also consistent with the aux St+ 33 42 green case loads.

Genkideskan, thanks for the excellent info. This is what makes the Forum so valuable.

Cheers, Lew


#14

Lew - you are absolutely correct about weighing loaded rounds. I have found that many of the proof loads in my collection run LIGHTER in weight than ball rounds. It could be they used a different powder, although not necessarily. The variations in weight of the various components - case, primer and bullet, DO obscure any study of powder charges by overall cartridge weight, at least in pistol ammunition. I just thought it would be interesting to weigh some rounds and see whatever there was to be seen. Once weighed, I decided to make them a permanent record for my files by recording them here, with the caveat that it really could not provide an answer.

I agree with you, as well, on what you said about pistol function. Blow-backs are more tolerant of lighter loads than locked-breech pistols, in my experience. Blow-backs are very intolerant of loads on the hot end of the scale, which would have no bearing on this issue. I discovered this while loading for the Makarov at a time when there was no Makarov ammunition available, nor any loading data, and everything was a guess and a gosh. The pistol functioned fairly well at .380 load levels, but when I pushed the loads a little past what they should have been for the Makarov cartridge, I got a bulge in the lower part of the case above the case web (base) and the cases did not drop back into the chamber. I was preparing various loads only two rounds at a time with each load at that level. I was very nervous about the process since it was my first go around with working with no published data. There was no choice at the time (1968). The powder-charge problem was worked out easily, for perfect functioning, but I never did overcome the problem of obtaining projectiles of the proper diameter, and abandoned the project. No one made a Makarov bullet mold in those days, nor any jacketed bullets for it.

Genkideskan - thank you for taking the time and trouble to help me with that. I will isolate that part of this thread and have it translated. I can read a little of it, and even that is helpful. Great stuff. I see that I was at least correct in that it was the Model 27 that was the primary silenced pistol used. I appear to have been completely wrong about the use of a reduced load, although I believe that I am correct that silencers don’t absolutely need such a load in this caliber to function. Depending on the silencer design, I suppose that a reduced charge would give less sound-signature and also, if wipes were used in the silencer, prolong the life of those components. I don’t know much about silencers - I never had much interest in them frankly, although that interest increases when the talk turns to ammunition for them.

Could you or someone fluent in German tell me the meaning of “zugrunde gelegt”? I believe it may be a critical phrase in understanding the sentence dealing with the velocity, and I can’t figure out the phrase just from dictionaries, although I know that “gelegt” is from the verb “legen” and I know “zugrunde” only as “ruining” something. I can’t put the two words together to mean anything relevant to the velocity of the cartridge. Obviously, I am completely missing their true meaning in this sentence.

Thank you.


#15

Well on these tested charge the production powder charge will be BASED.

Translating it word by word - the tested charges wouldt be [color=red]laid to the ground [/color]for production charges.


#16

Genkideskan - I think the first translation (“based”) is better for English. As you know probably much better than I, these phrases are often idiomatic and cannot be translated well word for word into other languages. It is now very understandable to me.

I wonder what the original velocity of the German Geco military rounds were? It seems to me the document established a powder charge that gives 294 mps (that’s 964 fps if I am doing the conversion well), which is certainly not a light load for 7.65mm Browning (.32 Auto) ammunition. It has been loaded hotter, but that “reduced silencer load” is probably still “hotter” than many normal commercial loads. So, while it undoubtedly represents a reduced load, it is certainly not an expecially light load.

Lew - BW has the Geco green-cased round, as I recall, and I have the FN one. However, I don’t know that either is really a silencer load. FN especially, was very sloppy with their primer sealant on the WWII ammo. Time and again people present regular ball rounds in FN steel-cased 7.65mm Browning as being “proof loads (Beschuss)” because the entire base is green. I have an FN Proof load in this caliber and case material from a labeled box, and the green base is an entirely different shade of green than is the primer seal that is usually seen on the “green-base” cartridges. I haven’t seen the Geco round for twenty or more years, but I seem to recall that the color was much like the “aux” 9mm loads. I don’t recall the case material and will contact BW to refreshm my memory about this round. The color of my FN round is much more like the primer sealant color, which makes me wonder, although the entire case is evenly covered with it.

I wish there was more documentation on the variations of identification of the German pistol-caliber silencer loads. What we just received is great, but still leaves unanswered questions as to identification.


#17

At the request of Lew Curtis, and with his assistance, I have translated the two documents that Genkideskan provided, to the best of my ability. Please understand that this is not a word by word translation, but rather simply how, I think the document would read if originally written in English, to the best of my ability to determine that. Some items written within parenthesis are not in the document, but are provided for clarification. For those not at ease with the metric system, I have added the figures originally reported only in Metric, in the “inch” form.

Document One:

Work Order Kummersdorf 19 November 1943 (Kummersdof was a military proving ground somewhat like Aberdeen Proving Ground is in the U.S.A.).

Determination of the loading for the silencer pistol cartridge for the Pistol Model 27 (Czech CZ Model 17) caliber 7.65mm, with silencer (Type) L.31.

Trial (Test): On 11 November 1943 at Kummersdorf.

Objective: Determination of the loading for the silencer pistol cartridge intended for firing from the Model 27 7.65mm pistol with silencer (Type) L.31 (ideal velocity approximately 290 meters per second and proof of accuracy performance at 25 meters). (NOTE: In this case, the entry in parenthesis ws in the text, not added by me).

Results: With a loading weight of 0.134 grams (approximately 2.1 grains) a velocity of 294 meters per second (964 feet per second) was reached. This loading weight will be the basis for the manufacture of the 7.65mm silencer cartridge. The accuracy test of eight shots fired from the Model 27 pistol with (type) L.31 silencer resulted in a group with a dispersion of 10 Centimeters in Height (Apprioximately 3.95 inches) and 9 centimeters in width (approximately 3.5 inches), with a normal point of impact.

Document 2 appears to be nothing more than a receipt. My translation here may bear more scrutiny than the above, as I am not positive that I have the point of who issued the items and who received them correct. I may have them reversed.

Einnahmeschein (I cannot exactly translate this word, but it appears to refer to some sort of a receipt - what we called in the Army a “hand receipt.” )

I will not try to translate this in good form, as I simply don’t have the German for it, but in essence, it seems to turn over from the Lehr Abteilung IV of the Lehr Regiment to the Criminal-technician Institute of the Sicherheitspolitzei (Security Police) and Sicherheitsdienst (SD - the internal Security Service of the SS), of Berlin, the following items:

1 Czech Pistol Model 27, caliber 7.65mm, with special barrel (this was a longer barrel with a bayonet lug-type attachment for a silencer, as I recall).

1 Silencer Number 31 (it has already been explained that “Haube” was a code word for “Schalldampfer” or “silencer.”)

1 Silencer Number 32 (I assume in this case “Nr. - number” is used in the sense of a type or model number)

25 “shots” with reduced loading (reduced charge).

The important thing about this document is that it confirms the reduced- charge ammunition was being used.

I hope I have this pretty much correct. My German is very limited and poor.
The Babel Fish" translation was of some help, but in some instances, caused more confusion than assistance, especially in regard to the receipt (Document Number 2).


#18

John and Lew that is in my opinion a very well done translation. You are right
a word by word translation is mostly not possible.
Well done.


#19

John,
would it be possible to post a foto of your 7,65mm Nahpatronen. Best would
be in comparison with the 9mm Nahpatrone.

Thanks


#20

From Left to right these cartridges are:

  1. “X” headstamped 7.65mm Browning Nahpatrone - steel case - red primer seal

  2. “X” headstamped 7.65mm Browning Nahpatrone - steel case - no primer seal

  3. “DWM 43 479A” 7.65mm Browning made at FN (Fabrique Nationale d’Armes de Guerre, Herstal-Liege) under the stewardship of DWM (Deutsche Waffen- und Munitionsfabriken A.- G.), entire case lacquered green. This FN round is of unknown purpose to me. It is included here because the all-green case would indicate a Nahpatrone loading. It is very likely though that the coloration is a result of the malfunction of the the primer seal-application machinery and that this is an ordinary ball round. The cartridge case is steel.

  4. “aux St+ 33 42” 9mm Parabellum Nahpatrone. Only known with this lot number. 9.72 Gram (150 Grain) bullet.

  5. “X” headstamped 9mm Parabellum Nahpatrone. 9.72 Gram (150 Grain) bullet. Steel Case.

  6. “cg St+ 21 43"” 7.9 x 57mm type s.S. Nahpatrone. Known in lots 1, 21, 23 and 25 of 1943. Also reported is the 7.9 x 57 type S.m.E.
    Nahpatrone with “eej St+ 8 42” with both a brass Model 88 primer and a steel Model 30/40 primer. It is assumed that those rounds also have the steel cases lacquered entirely green. This green color, as can be seen in the pictures above, is not to be confused with the various shades of gray and gray-green lacquer that normally protect German steel-cased ammunition from rusting (and other functions).

Shown in the same order, left to right, as the cartridges above. The “X” headstamp was done to absolutely conceal the point of manufacture, and while some may know where they were made in 9mm, I do not. I believe the “X” rounds in 7.65mm were made by Geco (Gustav Geschow & Cie, Durlach). The “DWM” 7.65 headstamp is identified above. "The “aux” headstamp on the green-case 9mm Nahpatrone is from Polte, Werk Magdeburg, and the box label indicates that they supplied the case and bullet and loaded this ammunition. “cg” on the headstamp of the green-case 7.9 Nahpatrone is Finower Industrie G.m.b.H., Finow/Mark.

Collection of John Moss