Jump to content

Accurate gun data?


SirReal

Recommended Posts

Is this for real?

Comparison of russian T34/43 76mm tank gun, firing APCR, and a german PzIVH 75mm tank gun, also firing APCR:

T34/43 APCR:

Initial velocity: 950 m/s

Grouping: 2.06

Penetration at 1000m: 92mm

PzIVH APCR:

Initial velocity: 990 m/s

Grouping: 2.06

Penetration at 1000m: 74mm

Are you kidding me? AFAIK russian ammo was of significantly lower quality than german ammo, not the other way around!

Oh wait. It's a russian developer. :rolleyes:

Link to comment
Share on other sites

  • Replies 69
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

I looked up the German gun data for a 75mm KwK 40 L/48, shooting APCBC PzGr. 39 ammo, and the 40 APCR. My source is test shot data from Aberdeen Proving Grounds Ballistics Laboratory using captured German equipment.

According to them:

APCBC PzGr. 39 ammo

Point Blank: 141mm

500 meters: 128mm

1000 meters: 115mm

1500 meters: 103mm

2000 meters: 92mm

2500 meters: 83mm

APCR PzGr. 40 ammo

Point Blank: 176mm

500 meters: 154mm

1000 meters: 133mm

1500 meters: 115mm

2000 meters: 98mm

2500 meters: 83mm

ToW's data for the same weapon system and ammunition is as such:

APCBC PzGr. 39 ammo

100 meters: 96mm

500 meters: 83mm

1000 meters: 69mm

1500 meters: 58mm

2000 meters: 48mm

APCR PzGr. 40 ammo

100 meters: 127mm

500 meters: 95mm

1000 meters: 74mm

1500 meters: 58mm

2000 meters: 45mm

I don't have data on Russian weapons systems, but I can dig it up in my technical manuals.

Another thing to keep in mind is that I don't know when the German samples used for test firing and their ammo was obtained. German ammo quality, although usually high, did decrease during the later parts of the war. If I dig more I'll find the difference it made.

Link to comment
Share on other sites

Originally posted by Normal Dude:

Lots of stuff, see above

Did you adjust for impact angle? You must have, otherwise the figures are way too high. Germans usually tested penetration at 30 degree angle - Russians generally tested at right angles. ToW doesn't state which, so we'll assume right angles for ToW values (1C are russian, after all).

PzGr 39

Distance -- RealWorld -- ToW

500 -- 128 -- 83

1000 -- 115 -- 69

2000 -- 92 -- 48

PzGr 40

Distance -- RealWorld -- ToW

500 -- 154 -- 95

1000 -- 133 -- 74

2000 -- 98 -- 45

So if your figures are correct, and the ToW figures are comparable (measuring steel penetration and right angles), then ToW data is, well, crap.

Link to comment
Share on other sites

The 500 meter penetration data between Aberdeen and ToW for APCBC and APCR differs by 36% and 39%, respectively.

For 1000 meters, the difference is 39% and 45%, respectively.

For 1500 meters, the difference is 44% and 50% respectively.

For 2000 meters, the difference is 48% and 55%, respectively.

That is a huge deviation, needless to say. I'm wondering if there is a fundemental difference in the how the two sets were collected that causes the rather linear difference in values. For example, as the range increases, notice that the penetration values become further and further apart. Also, the % difference between APCBC and APCR for each range category is about the same.

Link to comment
Share on other sites

Well, they seem to have taken most of their russian data from battlefield.ru:

http://www.battlefield.ru/index.php?option=com_content&task=category&sectionid=6&id=33&Itemid=49

This lists the Certified Penetration for the F-34 @ 1000m to be 68mm with good quality ammo -- the same gun in ToW is also listed with 68mm.

Of course, battlefield.ru also states that "Also, it is important to understand that realistic penetration values in 1941-1943 was reduced significantly due to low quality ammo."

Link to comment
Share on other sites

That also states that their criteria for determining successful penetration was different was well. It states that the Russians did not consider it penetration unless 75% of the projectile made it past the armor. The Germans used 50%. Maybe this accounts for the difference? I'll do the math and find out.

I honestly think that the data difference was simply due to how the tests were carried out. I haven't seen anything untowards during the game related to that stuff.

[ April 29, 2007, 08:16 AM: Message edited by: Normal Dude ]

Link to comment
Share on other sites

Originally posted by Normal Dude:

That also states that their criteria for determining successful penetration was different was well. It states that the Russians did not consider it penetration unless 75% of the projectile made it past the armor. The Germans used 50%. Maybe this accounts for the difference? I'll do the math and find out.

This could be a non-factor; we don't know how the distribution of penetration vs non-penetration is. Could be that it goes from 50% fragments inside to 75% fragments inside within such a short statistical span that using either criteria yields the same result at actual testing.
Link to comment
Share on other sites

I believe the russians guns and ammo was of okey quality, it was their optics that was inferior, very much so infact. So generally if they hit they could do damage, it was their ability to hit that was much lower than their german counterparts.

Link to comment
Share on other sites

Originally posted by seppDieter:

</font><blockquote>quote:</font><hr />Originally posted by SirReal:

Well, they seem to have taken most of their russian data from battlefield.ru:...

ok theres your problem, battlefield.ru is famous for its pro russian disinformation. </font>
Link to comment
Share on other sites

lol is this for real? geez, as a long time lurker of ic il2 forums, and a player of the il2 game, ive seen this stuff before.

im realy no "nazitanks should rock all" fanboi, but that putting the maingun of the t34/43 on the same level as the kwk40 l/48 is a sad joke, should be apparent.

Link to comment
Share on other sites

Originally posted by chanss:

</font><blockquote>quote:</font><hr />Originally posted by seppDieter:

</font><blockquote>quote:</font><hr />Originally posted by SirReal:

Well, they seem to have taken most of their russian data from battlefield.ru:...

ok theres your problem, battlefield.ru is famous for its pro russian disinformation. </font>
Link to comment
Share on other sites

The part everyone is forgetting is you are basing on what is in the encloypedia. I didn't work on that, but rather the internal numbers.

AGAIN, the numbers are based on works by various authors. If I can contact them again and get permission, I will post some of their information.

The numbers in the game for the t34 76.2mm L41 APCR @1000 METERS. 58mm

The number in the game for the Panzer IVH. I don't remember the model off the top of my head, but if it was the 7.5cm KwK 40 L43 APCR, then at 1000 METERS the penetration was 87mm.

Sources include: Solomonov 44, Zetterling 00, Jentz 96, Ellis 93.

Rune

Link to comment
Share on other sites

Oh yeah, all is based on 30 degree plate.

It is traditional to quote penetration against rolled homogenous armour of machineable quality (RHA or MQ). Performance against face-hardened plate, especially for smaller weapons firing uncapped rounds, can differ greatly. As a rule, it is expected that capped rounds will perform better than uncapped against face-hardened armour. It seems that there is a certain velocity band which face-hardened plate protects against best, and for projectiles arriving outside this velocity band, face-hardened plate is less effective than the same thickness of homogenous armour.

Armour hardness may vary considerably. During WW2 it was often measured using the Brinell hardness scale. 50 Brinell points corresponds to 10 tons per square inch (WO 185/171, “Armour plate experiments”); 1 Brinell point corresponds by my calculations to 0.315 Kg/sq. mm, or to put it another way 1 Kg/sq. mm is equivalent to 3.17 Brinell points.

Full credit to John D Salt, who reviewed the internal numbers used in the game.

Oh yeah, the internal figures match Bird and Livingston within 1 mm.

Rune

Link to comment
Share on other sites

Originally posted by SirReal:

Is this for real?

Comparison of russian T34/43 76mm tank gun, firing APCR, and a german PzIVH 75mm tank gun, also firing APCR:

T34/43 APCR:

Initial velocity: 950 m/s

Grouping: 2.06

Penetration at 1000m: 92mm

PzIVH APCR:

Initial velocity: 990 m/s

Grouping: 2.06

Penetration at 1000m: 74mm

Are you kidding me? AFAIK russian ammo was of significantly lower quality than german ammo, not the other way around!

Oh wait. It's a russian developer. :rolleyes:

Well said sir. You've just provided the technical proof for what most players are experiencing in-game and noting by 'feel'. Uber soviet tanks vs nerfed German ones.

No suprises there, we had the same BS foisted on us with IL2.

Link to comment
Share on other sites

BillyBob read Rune's post in this thread. I agree the encyclopedia should've beeen synced with the in-game physics model. The fortunate thing is that the accurate models got into the actual game. I will take his word that it was thoroughly researched.

Link to comment
Share on other sites

Originally posted by SirReal:

</font><blockquote>quote:</font><hr />Originally posted by Normal Dude:

Lots of stuff, see above

Did you adjust for impact angle? You must have, otherwise the figures are way too high. Germans usually tested penetration at 30 degree angle - Russians generally tested at right angles. ToW doesn't state which, so we'll assume right angles for ToW values (1C are russian, after all).

PzGr 39

Distance -- RealWorld -- ToW

500 -- 128 -- 83

1000 -- 115 -- 69

2000 -- 92 -- 48

PzGr 40

Distance -- RealWorld -- ToW

500 -- 154 -- 95

1000 -- 133 -- 74

2000 -- 98 -- 45

So if your figures are correct, and the ToW figures are comparable (measuring steel penetration and right angles), then ToW data is, well, crap. </font>

Link to comment
Share on other sites

Originally posted by rune:

The part everyone is forgetting is you are basing on what is in the encloypedia. I didn't work on that, but rather the internal numbers.

to be fair, the encyclopedia is all these people have to go by to judge the authenticity of the game's ballistic values, since apparently they do not have access to these "internal numbers" you are referring to. If the encyclopedia gives other valus than the game uses, then it is both a) 1C/BTS's fault and b)questions the point of having that encyclopedia in the first place. The way it is it seems to be way more of a problem than a feature / aid.

AGAIN, the numbers are based on works by various authors. If I can contact them again and get permission, I will post some of their information.

authors is rather unspecific. The Dorsch is an author, Im an author, everyone's an author... ;)

Sources include: Solomonov 44, Zetterling 00, Jentz 96, Ellis 93.

what kind of kryptic source quoting style is that?

and believe me Ive seen a lot of different quoting styles.

Zetterling, you mean his work on Normandy or the one on russian tank warfare co-authored with Frankson?

While Zetterling surely isnt the worst of works out there, I would definitely trust him more with organizational issues and not with hard technical details.

add-on: abovesaid notwithstanding, kudos to you and the work of the BTS/beta team on arriving at rexford/bird values.

Link to comment
Share on other sites


×
×
  • Create New...