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Resita 75mm AT gun shell comparison chart V4

Many thanks to my friend, Răzvan Bolba, with providing me with valuable research material about this gun!

 3rd and 1/2 EDIT: Someone pointed out to me that the PzGr 39 on the Pak 40 and Kwk 42 shouldn't have white tips, because that marking was used mainly on the PzGr 39 for the 76.2mm captured Zis-3.  I checked and... oops. Also, a discussion on wherever the Kwk 40 and the Pak 40- should have copper (KPS) or sintered iron (FES) driving bands led me to realise the PzGr 39 we would have gotten from the Germans in '44 definitely had FES driving bands instead of copper. Both are fixed now, Version 4.2.

3rd EDIT, 30.05.2019: In the time since my last revision, I was given scans of an actual period document called "TRAGERI DEMONSTRATIVE pentru OMOLOGAREA TUNULUI ANTI-CAR de 75 mm Md. D. T. - U. D. R. 943" ("Test firings for the homologation of the 75mm Anti-Tank Gun D.T. - U.D.R. Model 1943") and purchased a partial shell casing which has been demilled with extreme prejudice (cut to a third of it's length, holes drilled in the bottom and the side of the case punched), but which nonetheless retains it's bottom markings as well as some as it side markings... This is a good news-bad news situation, because, on the one hand, I now have tangible, first hand information about the Resita ammunition and it's markings, on the other hand some things have grown more confused and I have to remake this chart... It is now Version 4.1, including small revisions. 

First off, it is now confirmed that Romania never copied the PzGr 39 and the PzGr 40, we got them as they were from German stocks and mated them to the Vickers cartridge. This also means that the "Costinescu" round is a completely original design and nobody has any idea what it looks like, but some sources suggest it might have been an uncapped APHE-T...
Also, I'm still not sure wherever the "Nr. 4 md.1943 D.T." designation referred to the "Costinescu" or any of the German projectiles - which were officially known as "Obuz German Md. 939" (German Shell Model 1939 - PzGr 39) and "Obuz German Md. 940" ("German Shell Model 1940" - PzGr 40) - and I don't have confirmation the German shells were repainted, but this was done in the case of some French shells fired by the "tunul de câmp model 1902/1936 tubat amovibil FF-KF-RF" ("Field gun model 1902/1936 with removable barrel FF-KF-RF" - a modification of the Russian Putilov 1902 field gun adapted to fire either French 75mm ammunition, German 75mm Ammunition or Russian 76,2 mm ammunition) so I kept the inscription on the shell as it was and assumed it "Nr.4" is the PZGr 39. If more data shows up, I'll change it. 

Secondly, the manual gives the size of the Vickers/Reșița cartridge as 75X562mmR, rather than 561, as was apparent from measurements.

Thirdly - I revised the stencilling on the cartridge case, because even though the information was correct, the font, size, position and format were wrong, because I had based them on the wrong model. As it stands, the stencilling reads, from top to bottom: "M" - the code of the manufacturer, in this case "Metrom"; "2-44" - filling lot number and date; "GR. DL1-2 S1" type of powder filling; "13-44" - powder lot and date; "GTP 6800" - "Greutatea Tabulara a Proiectilului", the weight of the projectile, in grams. 

Finally, I added some inscriptions to the case of the 17 pounder, just because I thought it looked better this way... they are from a shell manufactured in Canada.

2nd EDIT, 27.08.2018: In my last revision I had gotten the text of the shell marking just about right, but the format was still a bit off (3rd EDIT: - Ha, no, it was waay off). I had been given a page from a period manual, but that only reproduced the general form and what the codes mean (For example "E1" is the code for TNT filling) rather than what font the stencils use, how they are spaced, etc. so I was somewhat still in the dark.
Luckily, in the meantime I got enough pictures of ground-find shells from metal detector groups to make a reasonably accurate picture of the format of said stencilling despite the fact in most cases it has survived only partially.

Another formatting mistake I had made was the placement of periods and dashes as well as proper abbreviation styles. For example, I had rendered "tun anti car" (antitank gun) as "T.A.C.", when the proper way to write it would have been "T.a.c.", something that had been under my nose all the while, because I had pictures of this exact marking on the breech of the actual gun, of which I have seen four in real life. Also, interestingly, in mid 1943 there was a move from abbreviating the word "number" as "No" in the French fashion (from "numéro") to abbreviating it "Nr." in the German style (from "Nummer"). Another thing would have been the placement of the dashes between the letters - the early war style was to have the dash placed one-third of the way up the letter from the bottom, which looked stylishly art-nouveau, but around 1943 the dash came to exactly half-way up, as on most contemporary fonts.

Finally, I got lucky because I've also been sent a picture of a crate label for shells which gave me the right filling information for the case - until now I had been using the markings off of a Romanian made postwar Zis-3 76 mm round, because that's as close as I'd gotten.

1st EDIT, 26.08.2018: After talking to some people who know a bit more about WW2 Romanian ammo than me, considering that my area of expertise is mainly centred around the late XIXth century and WW1, It appears that the blue-grey colour for anti-tank shells is postwar and that WW2 rounds were probably black, with the centering ring left bare metal. Also, I learned a bit more about Romanian shell markings and nomenclature, so the writing on both the shell and case is closer to what it would have been.

The drawing has been revised accordingly.

A personal non-fiction project. While trying to construct a 1/16th model of the DT-UDR 26, cal. 75 mm, Md. 1943 "Reșița" Romanian AT gun from WW2, I ran into a dearth of information regarding it's ammunition and decided to do my own research. This chart is one of the results.

Before we talk about that though, a bit of history.

After having been forced to cede territory both to the USSR and Axis ally Hungary in 1940,  the autocratic but ineffectual King Carol the IInd was deposed and power seized by a pro-Axis government led by General (later Marshall) Ion Antonescu, who suspended the Constitution, dissolved the Parliament and placed Carol's son, the 18 year old Mihai I on the throne as a mere figurehead, while he exercised actual control. Thus it comes as no great surprise that Romania joined the Axis in 1941 and marched east to reclaim the territory annexed by the Soviets in 1940.

We started the war utterly under equipped, in part due to disastrous mismanagement of the Army in the 30's by Carol the IInd and his merry camarilla.
In terms of anti-tank means, we started the war with a number of small calibre anti-tank guns, such as the French 25 mm Hotchkiss, the Swedish 37mm Bofors Md.1936, the Italian 47mm Breda Md.1935, the Austrian 47mm Böhler md.1935 and the French 47mm Schneider-Concordia Md.1936, and those sufficed at first, against lighter Soviet tanks such as the T-26, the Bt-7 and the T-28. However, as the war progressed, we ran into Soviet tanks such as the T-34 and especially the KV-1, against which these guns were completely and utterly useless. 
We needed a new anti-tank weapon, and fast. From 1942 onward our German allies provided us with a few examples of the pretty useful 5 cm Pak 38, the better-than-nothing 7.5cm Pak 97/38 (a modified version of the French 75mm M.1897 field gun, the granddaddy of all modern artillery) and the excellent 7.5 cm Pak 40 and we also had small numbers of captured soviet guns like the 45 mm anti-tank gun M1937 (53-K), the 76-mm divisional gun M1936 (F-22) and the 76-mm divisional gun M1942 (ZiS-3), but these were still but a drop in the ocean compared to the need for reliable, powerful AT weapons...

Enter a team of technicians from Uzinele şi Domeniile Reşiţa, led by Colonel Valerian Nestorescu, who after a few tests of mixing and matching various bits and bobs of various guns, concocted an amazing piece of shoestring-budget engineering, the bastard love-child of the 76-mm divisional gun M1942 (ZiS-3) (carriage and breech), the German 7.5 cm Pak 40 (projectile, muzzle brake and shield) and the British Vickers Model 1931 anti aircraft gun (barrel and cartridge), a variant of which had been in licence production at as the Vickers/Reșița Model 1936.

Visually, the gun is almost identical to the Zis-3, but if one is attentive enough they'll see that nothing is exactly identical to any of the sources - for example, the breech is slightly larger and more angular than that of the Zis-3, the muzzle brake is reminiscent but not identical to that of an early Pak 40, the barrel is monoblock instead of built up like on the Vickers, etc.

Finally getting to the thorny question of ammunition, the few sources all go back to the same report which is rather vague and merely talks about the main type of ammunition for this gun, which was purported to be the so-called "Costinescu" shell, a locally produced copy of the PzGr 40 (sic) German round weighing in at 6.6kg (sic) mated to a Vickers cartridge case and capable of a simply astounding 1040m/s (3rd EDIT: 1030m/s, according to the manual) and 235 tfm of energy at the barrel mouth, a net increase on even the Pak 40, which only achieved 990 m/s with it's lightweight 4.1kg PzGr 40 APCR shell and 790 m/s with it's APCBC round, the 6.8kg PzGr 39.

Well, maybe a little too astounding. First of all, the Vickers M.1931 AA gun has also been adopted by a number of other countries such as the Netherlands, Denmark and Belgium and by the Germans as captured specimens from the above countries, so we know the exact dimensions of the shell casing - 75x495mmR, and a straight casing, to boot. Mating that with a PzGr 40 APCR projectile would create a rather... underwhelmingly sized round, hardly capable of it's purported miraculous performance, especially when you consider the fact it's volume is smaller than the necked 75x495mmR cartridge case for the 7.5cm KwK 40 of the PZ IV let alone the whooping 75×714mmR of the Pak 40, which actually has roughly the same case geometry as the Vickers, but an extra 219mm of length...

Secondly, the PzGr (Panzergranate) 40 is an APCR tungsten cored round that was hard and expensive to produce even by Germany, which had an industrial capacity far in excess that of Romania and was thus fielded only in very small numbers and against hard to penetrate targets like the later IS series of tanks. For most targets, the Germans actually used the more "standard" APCBC-HE-T round, the PzGr 39. Moreover, as the above phrase suggests, the PzGr 40 actually weighed 4.1kg, so there's no reason why a Romanian copy would weigh 6.6kg, or almost the weight of the APCBC round, the 6.8kg PzGr 39.
Isn't it more plausible that the 6.6kg projectile would instead be a copy of the excellent PzGr 39 and somehow the performance data got mixed with that of a copy of the lighter PzGr 40 which probably also existed in small numbers? After all, even if we assume a roughly 4kg APCR projectile, 1040 m/s compared to 990m/s is a pretty substantial speed increase, which would suggest that the muzzle velocity of the 6.6kg APCBC round would be in the vicinity of 810 m/s (3rd EDIT: 840 m/s, according to the manual) , compared to the 790 m/s of the PzGr 39 out of the Pak 40. (3rd EDIT: Good deduction, but not quite on the money. We never copied the German shells, just used them outright. the "Costinescu" is an original design, as yet unknown)

Still, the question of the case dimensions remained, until, by a stoke of good fortune, a friend of mine mentioned he knew a guy who actually had an original cartridge case for the Vickers/Reșița Model 1936 AA gun. He provided me with pictures and measurements and, imagine my surprise to learn that the case was actually 561mm (3rd edit - 562mm according to the manual) long rather than the 495mm I had been assuming. This produces a rather more substantial looking round in terms of space for propellant charge, and, if one were to factor in things such as a hotter load, tighter tolerances on the barrel (also suggested by the fact the report states that barrel wear was substantial, meaning that barrel life was incredibly short, merely 500 rounds as opposed to 6000 for the Pak 40) and various other tweaks, the muzzle velocities cited become somewhat more plausible.

So, taking all of those into account, I created this chart, which shows the 75x562mmR round with the 6.6kg "Costinescu" projectile based on the PzGr 39 along with some other similar rounds - three German also using various iterations of the PzGr 39, the 76.3mm APCBC of the Zis-3 as well as the British 17.pdr AT gun, which is also produced by Vickers as a direct (if remote) descendant of their M.1931 AA gun.
The name comes from another report which notes the ammo available for the 75mm  Resita as "Nr. 4 md.1943 D.T." and "Nr. 1 md.1942C" AT rounds and the "Nr. 3 md.1943 D.T." and "Nr. 2 md.1942C" HE rounds. Of course, which is which is anybody's guess, so I just chose to name the APCBC as the "Nr. 4  md.1943".

Needles to say, if better info comes along and proves me wrong, I'll change the chart.

In terms of painting, I had a few good quality pictures of Romanian made ammunition used during the war, including a couple with visible case and projectile markings, and they all appeared to be light coloured (1st EDIT: yeah, they were HE rounds painted yellow, as per British standard - I initially suspected it, but wasn't sure and thus decided to go for the "light grey" interpretation, also drawing on my experience with WW1 ammunition) with stencilled black lettering in a certain format. Interestingly, even though we adopted a Soviet style of lettering on the ammunition we produced for our Soviet materiel, some of the ammunition factories, like "UPS Dragomireşti" and "S. Tohan SA" (the first founded in 1981 and the second which existed and produced ammunition during WW2 as "Malaxa") seem to have kept the marking style to this day close to that used during the war, which allowed me to extrapolate to what the painting and marking of this round could have looked like, especially since there have been ground finds of unexploded shells of Romanian manufacture with traces of blue-gray paint. 1st EDIT - it appears that the shells with blue-grey paint were actually of Soviet manufacture, and that WW2 AT rounds were actually black. Well, that's the reason I started this project in the first place, I knew nothing of Romanian WW2 ammo when I started...

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Thanks, this gun always makes people wonder on "where the heck is velocity coming from?" Thankfully some guy pointed me in your direction.

AlexDraco223's avatar
Hello there, this is really interesting and very well done. I found more info on the performance of the gun.
DT-UDR Table
(As you can see it's in Romanian, it talks about the performance of the DT-UDR 26.)
The weight of the projectile - 6.6 kg and 4.1 kg (most prob. Pzgr 39 copy and Pzgr 40) 
The muzzle velocity - 840 m/s and 1030 m/s (which makes sense)
Sources that confirms this:
1.Enciclopedia artileriei române
2.165 ani de existență a artileriei române moderne

Also could you make more rounds for the Resita? Like a bigger chart with the Pzgr 40 and with HE rounds? (Would prob be the normal vickers 1936 HE round and maybe a german one?)
wingsofwrath's avatar
I do intend do make a bigger chart of the DT-UDR 26 rounds, just as soon as I can get some reliable,  primary source information about them.

Right now all I have are third-tier information sources like the books you cited, and which I did know about.
The problem with them is that they reprint information uncritically from other sources stopping just short of outright plagiarism, because even the wording in those three books is suspiciously similar to one another and, presumably, to a fourth, as yet unidentified source.
In fact, the one you took the table from, "Enciclopedia artileriei române", manages to have discrepancies between the body of the text and the table at the back and checking the data against the two original manuals from the era I have in my collection (both from 1940, one for the "Tunul de câmp model 1902/1936 tubat amovibil FF-KF-RF" also developed by U.D.Reșița from the 1902 Putilov gun and "Obuzierul “SKODA”, calibrul 100 mm, model 1934") I found further discrepancies, so I wouldn't trust them too much. 

Yes, the table does seem to confirm my hunch that there was a PzGr 39 and a PzGr 40 copy for the DT-UDR 26 and the speeds these shells achieved, but until I can get an entirely independent source to confirm them...

Not to mention, I have seen conflicting evidence about the HE ammunition for the DT-UDR 26. Some sources claim that the HE shell is identical to the HE shell of the Vickers-Reșița 1936 AA gun and some claim it was a copy of the Sprgr.Patr.34 (the gun used two types of HE shells, so both could be right, or it could be that they're both the same shell but with different filling, etc.). And until I can get confirmation either way, there's not much I can do. Besides, I don't know enough on the ammunition for the AA gun either in order to make an accurate drawing, even if I did get confirmation. 
AlexDraco223's avatar
I see, maybe there are some veterans or people in the army that knows more about it. You could contact the arty school in Sibiu that has 1 Resita exposed, or search for the 357 battalion veterans.
wingsofwrath's avatar
I've already talked to some of them, because the guns themselves have been kept in inventory until 2000, but even the best recollections can't hold a candle to written documents, especially since the guns have been updated over the years, with new sights and new ammunition arriving in the 1980s (and I have one such sight at home, but it's really no help in reconstructing what the WW2 ammunition would have been like).
So, again, until I can get my hand on the primary documents...
AlexDraco223's avatar
I see, that's unfortunately, but new ammunition? That's new for me, be sure to include them in the chart when you get all the info you need. I m curious.
wingsofwrath's avatar
So, I've run into some more information about these shells and updated the chart accordingly - first off, even though there were new sights fitted in the 80s, there was no new ammunition, because I now have a partial shell casing that was demilled in 1993 when the guns were retired (not in 2000 as I initially thought, that's when they retired the Zis-2 and Zis-3) and it was made in 1944, with no refilling marks.

Secondly, we never copied the PzGr 39 and 40, we just used them as they were from German stocks. The "Costinescu" shell remains a mystery, but it was an original design rather than a copy.

Apparently, the HE ammunition was identical to the Vickers HE shell and the two types differ only in fuzing - timed or point-detonating.

The data you give in your chart is accurate. I found the primary source for it and I'm pretty sure this is where they got it as well.
PCFayard's avatar
Such beautiful chart! I need to know how you did the background!
The font is very nice! look like the handwriting version of technical fonts you can find on blueprints and SolidWorks plans...
gilll's avatar
From the thumbnail I thought this was a pic that explains different drawing pencils ^^;
wingsofwrath's avatar
Also, sorry to disappoint, but, if it's a chart of assorted drawing implements you're after, might I direct you to these two little drawings made by my sister? :D
wingsofwrath's avatar
Heh. they do look like pencils, don't they?

I'm guessing a boring ol' chart of WW2 ammunition is probably not exactly in your area of interest...
gilll's avatar
Nah, it's interesting, actually. I served 2 years in a military so I'm only a little bit familiar with ammunition. There are so many kinds of weapons and missiles all over the world and that can make your head spin :) I appreciate it when someone takes the time explaining them
wingsofwrath's avatar
Heh. Glad you found it interesting then. And yeah, forgot you have compulsory military service for everyone there. We used to have that as well until 1989, which is why both my parents were reserve 2nd lieutenants, my mother in the engineer core, and my father in the infantry. 

Speaking of which, what branch were you in? Personally, I've always been interested in artillery, but of course I ended up as a ground-pounder and ceremonial guard, because what you want and what the army wants are two different things...

Also, let me congratulate you on your gallery, you have very expressive art style! I've always been jealous of people who can draw faces well, because I usually end up with wooden puppets whenever I attempt it. XD
gilll's avatar
Thank you very much!
Place a small mirror on your desk so you could look at your expression when you draw a face. That's how I started :D
Also, watching cartoons helps!

I was in the intelligence branch. A lookout, to be exact. It wasn't really expected of us to know that much about artillery, 
but we needed to at least know the differences between small rockets big missiles, haha :)
wingsofwrath's avatar
Ooh, now that's a good idea and not one I've heard before.
At this point, I can definitely call myself a "professional" artist, and even though I have tried may things before, such as life drawing, drawing after photos, etc. and my art has grown better, drawing faces never got to the level that I wanted it to be... So I'll definitely give it a shot.

Definitely an important job, but probably not the most riveting experience, I imagine. Since I've done my share of guard duty, I'm assuming lookout duty must be pretty similar, standing mostly in one place, being bored out of your skull...

gilll's avatar
Yeah, it was often very boring and I bet it's very similar to guard duty...making sure that everything was in order and that there was no suspicious activity happening.
We used to sing and play games to pass the time (4-6 hours per shift)...
AndreaSilva60's avatar
Great job indeed, chapeau!
AriochIV's avatar
Forgive me for not reading the whole description, but are these all real ammunition examples? We have 6 rounds, none of which share the same caliber OR length, meaning none can be fired from the same gun. It sounds like a colossal clusterfuck.
wingsofwrath's avatar
Yup, those are all real AT rounds belonging to several guns used by various nations during WW2.
The point of the drawing is to compare them all to the round used by the Romanian AT gun, the 75mm Reșița M.1943 (third form the left) because the Reșița was an amalgamation of several design features from several nations and used details from all of these guns. For example, the main AT projectile was a copy of the German PZGr 39, which was also used on the gun for the Panzer IV (second from the left) and Panther (fifth) tanks and the Pak40 towed antitank gun (sixth). Needless to say, even though they all used the same projectile, their performance varied due to the different case dimensions, barrel lenght, etc. The others are a Soviet round from the Zis-3 76.2mm gun (the Reșița 75 used a n almost exact copy of it's mounting and recoil recuperators) and the British AT 17 pounder, because it and the Reșița 75 were both designs based on the same gun made by Vickers, the Vickers M.1931 AA gun, which was also made under licence in Romania in the late thirties.

AndreaSilva60's avatar
You didn't read the plate's captation too ;) They are all different shells for differrent guns, there are three  German shells, one for pak 40 the other for the cannon of the panzer IV and for the panzer V, there is a russian one, the first from the left, with cyrillic characters, and the clearly british one with its funny caliber in pounds (pdr),  mounted on Firefly, Challenger and Centurion.
TheAsianGuyLOL's avatar
Wow! An awesome research of just an ammunition! :D
wingsofwrath's avatar
Thanks! It turns out more research was needed, hence why I had to revise the drawing. Opps.
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