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Thread: German 7,5cm KwK 40 Spregranate Patrone

  1. #1
    EOD - bombs and bullets pzjgr's Avatar
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    Default German 7,5cm KwK Sprenggranate Round

    So, I have had a German 7,5cm KwK HE round since the middle 90's probably...bought off eBay when ordnance was plentiful there, and bought from Europe where it was relatively cheap, and had no problem getting things delivered. Thus was the Golden Age of German ordnance collection, really. A ton of stuff was surfacing, literally, there. Most of it water or ground recovered from large wholesale disposals at the end of the war..,pits dug and ordnance and ammo bull dozed in, or just dumped into lakes and such. As there was a good market for it, it was being recovered, demilled, and sent wholesale around Europe and to the states. All over eBay, dealers with vast inventories.

    Now it was never "Cheap", but it was reasonable, and if you ordered lots of stuff with the same vendors, you built a rapport, and got unlisted stuff.

    Never had an issue with stuff coming in, until 9/11, then the spigots shut off. So difficult to get shipped now, with a loss rate of 50% or better, and crazy prices...getting stuff from Europe is tough on many levels now.

    Anyway, got a round, looked water recovered. The projectile was great...the steel case, not so much. Perfect for display on one side, rather rusted/pitted/perforated on the other. So being a relatively unskilled kid, I sort of did my best with body filler, sandpaper and impatience, and did a mediocre job at fixing the one side, sprayed it with brass spray paint, displayed it with the good side out, and called it good...

    The case never really sat right with me, then a buddy from up north called a few weeks ago, and asked what this big case was...why, its a KwK 40 case, what are you going to do with it...sell it to you he said. So we agreed on a price, and he sent it off, got it Saturday.

    An upgrade to say the least.

    So I pulled the projectile from my old case, (which I will likely re-work, do a better job on the bad side, figure a way to paint it so it looks decent, and likely put it up here for sale), took some detailed pics of everything, re-seated the projectile in the new case, and Bob's your Uncle, a really awesome finally complete KwK 40 round!

    The KwK 40 gun was an AFV gun (Kampfwagen Kanone) in the 75mm flavor, which supplanted the short barreled KwK 37.

    The KwK 37 was also 75mm, but the barrel was L/24, or 24 calibers in length, or roughly 70 inches in length. It used a short cased, straight walled round. These are the guns mounted in the StuG III Ausf. A-E, and the early short barreled Pzkw IV tanks. They were relatively low velocity, short range weapons developed mainly for infantry support, as the early Stug's and Pzkw IV's were intended.

    Of course being low velocity, they were relatively anemic against armor (the main contemporary anti-tank gun was the 5cm, but was quickly found lacking too), so a more powerful 75mm gun was needed. The KwK 40, L/43 and L/48 guns were developed, with a much longer bottlenecked case. This greatly increased the velocity of the projectile, and had a huge increase in lethality against armored targets.

    These new guns were used on the long barrel Stug III's, Ausf F-G, and the Pzkw IV Ausf F2 and beyond...Technically if the gun was mounted in a Stug, it was the StuK 40, but the ammo is the same.


    Here are pics of the KwK 37 HE round, and the KwK 40 HE round...same type of projectile in both, you can see the KwK 37 case is about the same length as the case, while the case on the KwK 40 round is more than twice the length of the projectile.

    More to come later...
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    Last edited by pzjgr; 09-09-2019 at 06:38 PM.

  2. #2
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    Interesting post. They look like they would hurt. Hope to read more.

    Sent from my XT1585 using Tapatalk

  3. #3
    EOD - bombs and bullets pzjgr's Avatar
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    Case....This is a later 1943 manufacture steel case...

    The headstamp reads at the bottom, 6339 St, and 7,5cm KwK 40...6339 is the German numerical designator for this case, St denotes it is made of steel (if it were brass it would just have the 6339 designator), and 7,5cm KwK 40 is the gun it is made for.

    There is a WaA acceptance stamp at the 4 o'clock position.

    aux 43 is the where and when the round was loaded, and bzs is where the case was manufactured. Not sure what the number is stamped below bzs, I'll have to look at my references...

    All KwK/StuK guns were electrically primed. There is an earlier 1939 C/22 brass bodied electric primer I put in it, since there was no primer in it when I got it...always like to have a few primers stashed away for something like this. It would more likely have a C/22 St steel primer in it, but brass will do for now. If you find a percussion primer in a vehicle gun case, it is wrong.

    All in all, this case is decent. Solid, no major through and through corrosion, just some light surface inactive corrosion. I could try and wire wheel it, but likely won't it has a pleasing look as is to me...
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  4. #4
    Community Organizer Hambone's Avatar
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    Very cool, congrats on the case Did the Germans use a standard primer/fuze across many rounds?
    “Not every item of news should be published. Rather must those who control news policies endeavor to make every item of news serve a certain purpose.” - Dr. Joseph Goebbels, Reich Ministry of Public Enlightenment and Propaganda, 1933-1945

  5. #5
    EOD - bombs and bullets pzjgr's Avatar
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    Quote Originally Posted by Hambone View Post
    Very cool, congrats on the case Did the Germans use a standard primer/fuze across many rounds?
    Yes, they did tend to use the same fuzes/primers across a range of guns/calibers...

    For example the C/22 primer was used on most (if not all, but I would have to double check) big bore ammo from 5cm to at least the 15cm, with percussion for ground guns/artillery, and electrical for the vehicle guns. But the size, shape, and threads were the same of all of them which is why you could swap between electric and percussion types.

    3,7cm and 2 cm used different primers, the 3,7cm stuff used a smaller screw in primer similar to the big boys, and the 2cm stuff used a pressed in primer much like our 20's and .50cal stuff...

    This Klaz 23 (umg) is the small noze fuze 23 (improved)...this simple impact fuze was used in 3,7cm HE, 5cm HE, and 7,5cm vehicle gun HE rounds...7,5cm artillery (like the infantrie geschutze, and gebirgs geschutze) used a large fuze, and anything bigger than 7,5cm used larger fuzes.

    The large fuzes can get complicated, as there were a myriad of varieties...but generally the fuze opening diameter and threads were the same.

    Almost all German war shot AP from 3,7cm and up typically were explosive filled and base fuzed, with delay. The idea being that detonation of the filler would delay log enough for the shot to penetrate the armor or building, and then go off, which would make it an extra bad day for those inside the vehicle...again, many of the base fuzes were used across the board...

  6. #6
    EOD - bombs and bullets pzjgr's Avatar
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    The projectile...

    The projectiles were cast steel. These 7,5cm Sprenggranate had a slight boat tail, and I don't think ever had tracers. Then you can see the cannelure groove which is how it was crimped into the case, then the driving band, which in this case is sintered iron (which can be seen visually, but almost always included the stenciled designation FES, which you can make out on this projectile).

    Above that is the straight walled body of the shell, then you can see a slightly wider band called the bourrelet. The thing about artillery and large gun projectiles, the bourrelet is the only dimension (typically) on the projectile itself that has to meet close tolerances. The projectile rides through the barrel on the bourrelet and the driving band. The bourrelet is a relatively narrow band to keep the co-efficient of friction down. If the entire projectile body rode the barrel that introduces a considerable amount of extra friction which would slow the velocity of the projectile, and wear the barrel much quicker.

    From the bourrelet forward it is typically known as the ogive, the curve that brings the projectile to a point and streamlines it. The end of the ogive is the fuze cavity in HE shells, where the fuze screws in. Typically a fuze for anything bigger than 3,7cm will include a gaine, or extra explosive charge that screws into the base of the fuze to ensure the detonating force reaches deeper into the cavity of the shell to help ensure a good high order detonation of the filler. Most fuzes you find that are inerted are missing the gaines…

    Stampings on the projectile designate the place and date of the manufacture of the projectile body, and also the place and date of filling and fuzing (or plugging if shipped separate from the fuzes, usually in big stuff 15cm and up...)

    This projectile retains much of its original paint, although the stenciling typical other than the FES stencil, is gone...but its in too nice an original condition to mess with.
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  7. #7
    Maple Syrup Mod Eh CanadianAR's Avatar
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    Nice upgrade, Looks great!
    Looking for 10" cleaning rod, early style e/214 #91, nazi style e/26 #04

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    Senior Member mauser202's Avatar
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    Sweet, love the write up too.

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