About Pak40's penertration data on German side

[xellos]

Why pak40's vel data on the document is 750m/s?(792m/s in cm)

And its penertration data also seems much weaker than CMBB's data(I dont know cmbn's data)

[Pak40]

The girls have never complained about my penetration data.

[iMolestCats]

The girls have never complained about my penetration data.

HAHAHAHA aw man you killed me!

[akd]

The girls have never complained about my penetration data.

Guaranteed FTP, low risk of spalling. Pretty safe for the ladies.

[YankeeDog]

Careful. Each major combatant in WWII had a different standard for what was considered a "penetration" in armor vs. projectile tests. I don't remember all of the details off of the top of my head, but suffice it to say that without knowing the testing standards, you can't really compare data of gun 1 from nationality A to data gun 2 from nationality B because there may be fairly different criteria involved.

For the data in CMBB, BFC obviously had to conform the penetration data for all projectiles to a constant standard regardless of nationality. I don't remember offhand what that standard is, but I do remember that there is one.

As far as the velocity, hard to say... one wonders if this varied through the course of the war as manufacturing techniques changed.

[Peregrine]

Not entirely sure if this is relevant to this situation but while developing I am sure Battlefront mentioned new reference materials/data for many aspects, so CMBB data may be quite different to the CMBN mechanics apart from what was required to fit the numbers in with the new engine.

[Vanir Ausf B]

A quick and dirty cut 'n paste from Wikipedia.

The muzzle velocity was about 790 m/s (2,600 ft/s) as opposed to 750 m/s (2,500 ft/s) for the KwK 40 L/43. This velocity was available for about one year after the weapon's introduction. Around the same time, the Panzer IVs 7.5 cm KwK 40 L/43 gun and the nearly identical Sturmkanone (StuK) 40 L/43 began to be upgraded with barrels that were 48 calibers long (L/48), which remained the standard for them until the end of the war.

In the field, an alarming number of L/48 cartridge cases carrying the hotter charge failed to be ejected properly from the weapon's semi-automatic breech, even on the first shot (in vehicles). Rather than re-engineer the case, German Ordnance reduced the charge loading until the problem went away. The new charge brought the muzzle velocity down to 750 m/s (2,500 ft/s), about 10 m/s higher than the original L/43 version of the weapon. Considering the average variability in large round velocities from a given gun, this is virtually negligible in effect. The first formal documentation of this decision appears on May 15, 1943 ("7.5cm Sturmkanone 40 Beschreibung") which details a side by side comparison of the L/43 and the L/48 weapons. The synopsis provided indicates very little difference in the guns, meaning the upgrade had little if any benefit.

All further official presentations of the KwK 40 L/48 ( "Oberkommando des Heeres, Durchschlagsleistungen panzerbrechender Waffen") indicate a muzzle velocity of 750 m/s for the gun. As for the Pak 40, the desire for commonality again appears to have prevailed since the APCBC charge was reduced to 750 m/s, even though case ejection failures apparently were never a problem in the Pak version of the gun.

[winkelried]

A quick and dirty cut 'n paste from Wikipedia.

so size (/43 to /48) really doesn't matter ... more if you're on the move or static (at least for the ejection)

[ArgusEye]

Do you have a bigger pic of the data sheet? I find it quite hard to read.

[Michael Emrys]

never mind.

Michael