That first cut away isnt a 50% Cut away, so the pixle counting doent work. Its especially visible at the base that its “Just a Cake Piece missing”.
In other words, you cant see the full core.
Fair enough!
Here’s the other core, it’s easier to use this one
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Sooooo one quick crash-course in Blender, and here I am!
5435.56mm^3 = 5.43556cm^3
If we assume the density of Tungsten Carbide is 15,63g/cm^3, then this penetrator core weighs 84.9578g or ≈ 85g
So now 85 out of 108 grams is accounted for.
The remaining 23g of projectile weight is probably the aluminum nose cone and/or base plate? I will try to model these later
Update:
Phew, I modeled all the major parts!
Aluminum “Base” Cap - 16.83g
Tungsten Carbide Core - 84.95g
Aluminum Nose Cone - 1.17g
Plastic Sabot - 6.47
It all adds up to 109.4g, only 1.4g over the specified weight of 108g
This difference may be due to modeling errors, different densities, and/or missing tracer cavity (in the core)
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Weird, is that really the entire tungsten carbide core?
It has that subcaliber tip, which seems rather odd.
Maybe explains some of the performance results.
I remember that the round struggled to penetrate more than 60mm of armor, most likely because of that tip.
I can only assume that the design is a compromise for overall good penetration at all angles, and that the tip, probably breaking at higher impact angles, reduces the amount of deflection the round is going to experience at higher impact angles.
Edit: I think I was thinking about M601 when I wrote that, which should be the same as DM43.
There was this US document that showed that the 0° penetration was somewhat lacking.
But they just have a regular sharp tipped tungsten carbide penetrator, unlike the DM63.
So I’m not sure what’s going on.
Yes, it seems so! It looks like that in all the cross-section images I could find.
I’ve been dabbling in Ansys, I will definitely try angled performace after I get this figured out!
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Bumping this for attention, since this effects so many vehicles in game. And now we appear to have the SuperHind using this ammo, as well as the Luchs (obviously). Its still shocking how drastically worse this is in game compared to reality.
Oh yeah it’s been a while
Some other stuff popped up IRL so the whole 20mm ordeal got put on the back-burner
And ANSYS Student wasn’t really suitable for the tests I was after, I don’t think I’ll pay up for a full license
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Understandable, this is just a personal obsession of mine. Its extremely unfun and just unfair using vehicles with this ammo especially while every other autocannon is performing quite well and very useable. I guess the germans and french just don’t deserve a decent autocannon.
Just found this thread after noticing how poorly 20mm HVAP on coax guns like used on the new CLOVIS perform (Its WORSE than a .50 cal when it comes to penetrating angled armor, and struggles agains stuff like the Ontos)
Has anyone made a bug report regarding this discrepency in performance compared to real life? I don’t mind if the vehicles using a 20mm have to go up in BR because of this. I love Warthunder because it tries its best to mimic IRL performance of weapons, and I hope the devs look at this and do the same.
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Germany has the best in the Leopard 2K.
France have always had it rough with the 20mm COAX on their tanks doing close to no damage
do you realize that they shoot the same round right? the damage is the same.
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hold on,i really doubt the data in this pic
u mean the 3ubr8 has only 38mm vertically penetration at 1000m,while the 20mm dm63 with much more smaller caliber & propellent can deal twice more???
i wonder the source of this pic,the penetrtion of 3ub8 seems ridiculous! its hard to believe it has only 38mm at 1000m,even worse the 20mm avap
yes that is how a sabot round works
It’s really strange. You’d have to look at the weight of both bullets, the weight of the penetrator and the cap, the piercing material and its shape to compare them properly, but it’s still strange that a 30mm bullet has less penetration than a 20mm one.
It’s not, considering it’s Soviet ammunition.
Just look how pathetic their WW2 APCR round are.
The only time the Soviet Union had any advantage in tank ammunition was when they invended APFSDS, and even then it was just some steel rod or a rod with the tinest amount of tungsten carbide in the tip.
The ammunition they produced was always “good enough for the job” but never outstanding.
Spoiler
This is supposed to be 30mm 3UBR8. It’s low res and not ideal for meassuring sizes but the core is roughly 11-12mm at its thickest. That’s around the same thickness as a German WW2 20mm Pzgr. 40 core.
It’s longer and heavier but you can’t expect much penetration out of that at 1000m.
So a modern 20mm APDS is going to beat that simply by losing a lot less velocity.
The German 30mm WW2 APCR used 16x85mm cores for example. So the low performance of the 3UBR8 isn’t really suprising.
Edit: Actually I’m wrong about something. I thought the round was supposed to be APCR but it’s infact APDS.
However, it’s supposed to use a tungsten alloy core, which would greatly decrease the vertical armor penetration. But this would also increase the sloped armor penetration.
So the chart is probably wrong about something. Maybe they knew about 90° penetration but then assumed it was tungsten carbide, thus they gave it worse slope performance than it should have.
So while the 90° figure is probably correct, the slope performance doesn’t match with a tungsten alloy core.
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That’s what I was looking at for example about the 100mm APDS-FS 3B25, which in the game in principle has less penetration in reality (because apparently they used the data of the 3BM20, and even so it would be worse than in reality). According to what I saw, the Soviets developed at the same time the 100mm 3BM25, the 115mm 3BM21 and the 125mm 3BM22, using essentially the same design, with the difference of the different muzzle velocity of the different barrels, and that really only differed from the previous ones in that the cap instead of being made of steel or tungsten carbide, was made of tungsten alloy, being a steel arrow, with a core at the tip of tungsten carbide (thicker than the previous APDS-FS of 100mm), having in front a cap with a flat tip of tungsten alloy, making them penetrate somewhat more than the previous versions of the 100, 115, and 125mm cannons. What I’m saying is that, in principle, the improvements to the Soviet APDS-FS shells were somewhat marginal, with minimal improvements and a small improvement in 60° penetration performance.
Because of this, I don’t know how the Soviet 30mm APDS would work, and whether the German APCR and 20mm APDS would have designs that would be superior to the Soviet ones.
where is the sources about those test on t62
Well, I don’t really know. I found those images on Twitter, where they were talking about that ammunition.