Don’t you need to make a bug report or something like that?
Best winrates and k/ds amoung other nations.
According to a drunk russian youtuber LOL.
More trustworthy than almost everyone on this forum
Of courseeeeeeeeeee.
Would be nice if they got that sorted out. My suggestion to add core diameter and weight to the stat card was submitted to the devs but nothing yet. I have a feeling they don’t use accurate core sizes as a way to balance the rounds.
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The mass of cap + windshield of the M62 projectile is 18% of its total mass. From this comparison it looks like the percentage for the 90mm shell is even higher, due to the cap itself being thicker and the penetrator’s body shorter.
18% of 7kg equals to 1.26kg. Scaling this up times (90/76)^3 = 1.66 we get 2.09kg, the lower bound for the cap + windshield assembly for M82 projectile. Which is 19.1%. The actual value might be ~22%.
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I think your 22% estimate is correct for the M82. That’s about the estimate I got when I modeled it on my computer.
Using your reference of the 39/42, the 76 mm should pen about 143 mm and the 90 mm should about 176 mm. 76. Did have issues with heat treat so that must be why it fell short. The 90 mm was closer but short by about 6 or 7 mm.
Really? Nice. That was just a wild guess, btw. :)
What “my reference of the 39/42” are you talking about? Yeah your estimate looks fine, if we lower the german ballistic limit by 4% to convert it to a 50% success criteria.
I meant the PzGr 39/42 without the cap penning 140mm at 762 m/s.
But why would you calculate how much would it pen w/o it’s AP cap and use it as reference to estimate the penetration of the US capped shells?
I was curious how the other rounds would perform based off the penetrator weight alone. The PzGr 39/42 is a high quality round that showed serious toughness, so I wanted to see what the hypothetical penetration would be if the issues with M62 and M82 were ignored.
The M82 performed relatively well according to its penetrator weight but the M62 under performed quite a bit.
Yeah, I see. I am using the 7.5cm Pzgr. 39 shell as a reference as well when I need to make some estimates.
Sure about that? The cap on the M62 looks somewhat bigger and the windshield is huge compared to the 75mm Pzgr. 39 🤔
Yeah, this is not an estimate I will post tomorrow the page from the document were it says it.
The penetrator of 7.5cm Pzgr. 39 is 5.925kg, figure taken from historical German source. So it’s cap+windshield are ~12.9% of total mass.
Edit:
This is not the mass w/o the fuze and filler as might be tempting to assume at first glace, because the M66A1 fuze weights at 1.04lb.
In US methodology it is usual to report the weight of APCBC shells without taking into account the mass of their BC:
So, this one should be interpreted as:
The mass of the M62 APC without cap and WS is 14.7lb - 13.9% = 12.66lb. (5.74kg). This is 82% of it’s total mass (15.44lb)
I would like to thank @MiseryIndex556 for providing the data about the T50E1 shell.
External ballistics of two shells are assumed to be identical.
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According to the Table of Form Factors, the M82 and T50 have similar ballistics.
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Can you continue it to 3200 fps?
The NPL formula is not meant to be used for velocities above 3000fps, but I don’t think there will be much error if we extrapolate it at 0° obliquity.
I have added the german long 88mm for comparison.
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Superior German Krupp Stahl 😜
(I know it’s slower :P)