Overhaul of Gaijin calculator

For Soviet APHE and APHEBC, the setup is similar to APC but a .7x modifier is applied to the total round weight instead of a .9x.

Here is a chart for the ZIS-S-53 on the T44.
IMG_7128

3 Likes

I’m curious about the Soviet 100 and 122mm ammunition, because they seem a bit strange to me, firstly the 122 sharp and the flat have the same penetration at 0° when the sharpened ammunition should have a bit more penetration at 0°, and then there is the APCR of the 100mm cannon that drills less than the APCBC.

Gaijin doesn’t differentiate between the sharp and blunt AP designs when calculating penetration. For the 122mm, I believe the AP and APBC have the same HE filler, so their penetration comes out the same. From that point, the only difference is their ballistics. The APBC maintains its velocity better, so it loses less pen over distance.

1 Like

But it would actually affect penetration, right? For example, there is also the M82 90mm ammunition whose nose is much more rounded than the M77 and the T33. Apart from that it would also depend on the strength of the nose, right?

It should affect penetration. Sharp nose and blunt nose rounds use different mechanisms to penetrate armor. The issue is Soviet metallurgy was so poor, the sharp nose rounds were not very effective. The blunt nose was meant to reduce shattering.

1 Like

Here’s some data I’ve seen on the Soviet 100mm. The BR-412B is over performing by quite a bit.

Protection limit considers a penetration to be when the round produces spalling on the inside of the plate. Even at that low level of standard, the BR-412B was only rated at 7.01” or 178mm. And that was using cast armor.

5 Likes

On one hand the graph says it is overperforming against flat armor.
On the other the graph also says it would go through over 100 mm of cast armor at 60º (granted, protection limit, according to your comment).

I’ve seen a simulation that explains this better. Russian rounds had poor metallurgy as you said which caused them to shatter. It seems that this same shattering also made it so they performed better against angled armor, much like T33 APBC. It seems that their real life performance against angled armor came from the shattering characteristics of the round rather than the blunt nose itself.

Yeah, the Soviet blunt AP should more or less match pointed AP against sloped armor but I think it was better against under matching armor. I’m not entirely sure.

Just for reference, the T43 (T33 from the long 90mm) would pen 280 BHN 4” cast armor at 60 degrees at 3007 fps. That’s using army standard, not protection.

With some help, I gathered a bit of information about German APCR. Using my suggested changes, here’s how a few of them would look.

PzGr 40/43: 2.0 kg 36mm core at 1130 m/s is 313mm.
8.8cm PzGr40: 2.0 kg 36mm core at 930 m/s is 237mm
PzGr 40/42: 1.12 kg 30mm core at 1130 m/s is 252mm
7.5 cm PzGr 40: .90 kg 28mm core at 990 m/s is 192mm.
5 cm PzG4 40: .34 kg 21mm core at 1180 m/s is 169mm

2 Likes

I’ve made some updates to my changes. The APCR modifier was changed from 1.25x to 1.37x.

1 Like

Comparing my results to some posted by Peasant in another thread shows the AP and APCR results are reasonable for Soviet style as well. The APC is known to overestimate many APC rounds but I don’t know of a reliable way to account for various cap sizes. It would have to be done on a round by round basis.

IMG_7128

1 Like

Here are a few 90mm tables.

90mm M3 Early

90mm M3 Late

90mm T15

2 Likes

100mm D-10T chart. Replaced BR-412P with 3BM-8 APDS, based on limited info I could find.

1 Like

If anyone wants to know what certain rounds would look like, PM me the information and I will make a chart.

That is definitely true of wartime ammunition, American analysis of 45mm,57mm and 85mm APHE captured in Korea (Report ADA443218 which is publicly available online), they also consider the shapes used obsolete.

It’s interesting how the Soviets adopted capped AP by using German rounds as references, while the US dropped capped AP.

Is it possible that it was because the Americans realized that it was better to have more penetration at 60° in exchange for losing penetration at 0° while the Soviets continued to prefer penetration at 0°?
The bad thing is that it is not reflected in the game, since the APCBC drill at 60° the same or more than the APBC.

1 Like

That’s likely the case. It’s just something I found interesting.

That makes sense.

It must also be taken into account that the APCBC BR-412D ammunition is from 1953, so one could say that it was put into service quite late since the HEAT-FS of the 100mm cannon is from 1955.
Of all, I would not be surprised if they kept the BR-412A ammunition for the tanks destined for export, for example in the Yom Kippur War the arab T-54 and T-55 used the BR-412D ammunition, instead of the HEAT-FS or APDS, which were already available for the Soviet army.
That’s why I find it funny, the T-54 should have the BR-412A as the best ammunition, the T-54A could carry the BR-412D and the HEAT-FS, and the T-55 would carry the previous ones plus the APDS.El Tiran 4, being captured from the Arabs and maintaining the 100mm cannon, it would carry the BR-412D, I imagine that is why the cannon was replaced by the Western 105mm, apart of course from the fact of not having spare cannons and ammunition manufacturing.