Summary of the Russian 76mm against 80mm StuGs?

[Mr. Tittles]

This pic shows a StuG w/saukopf mantlet and the gun raised very high. Notice that the back of the mantlet has a vertical piece just like the early mantlet does on a StuG B.

The reality might be that all StuGs had 'double-protection' where the flat mantlet piece overlaps the fighting compartment wall (50mm+50mm). According to reports, the mantlet was face hardened (not the cast pigs head though).

Even the G version with 'box' mantlet may be better armored than many think. Its a complicated layout of armor on the vehicle, and it is such an important axis weapon, and deserves proper modeling.

[Mr. Tittles]

Originally posted by Mr. Tittles:

The lighting here clearly shows that there would be a path to the very back armor behind the gun (50mm) on these box mantlet StuGs. Its a small area but still a weakness.

Edit: That area is actually part of the mantlet! Behind it is the front fighting coompartment wall (also 50mm). The main potential weakness would be the front of the mantlet box. Behind it may be the gun itself and a path to the interior. The pigs head mantlet would eliminate this weakness.

I just want to show the updated edit again.

[Redwolf]

Looking at StuGs it is pretty obvious to me that the 80mm armor will be a little less than 80mm for most shots because of edge effects. The fragmented surface comes at a price.

[Mr. Tittles]

You must mean the drivers plate I assume? The bow 80mm armor is actually the best armor on the vehicle, especially the small sloping upper bow armor.

[K_Tiger]

I was thinking we discuss advantages/disadvantages from the real ones. In Game therms, the über/ situation from the 80mm Stugs resulted in the fact, that the current CMBB engine cant handle so many different surfaces in one single front armor. So we have to life with the overall 80mm.

Dont underestimate weak spot pennetrations or gun damage, in one of my last CMBB QB i lost all of my 4 JPanthers due to Gun damage in a couple of turns.

[YankeeDog]

Like I said, if it is actually true that the Stug frontal armor resisted like less than 80mm due to edge effects on a significant percentage (but not all) hits, this clearly could have been modeled in the current engine, either by using the exact reverse of the same mechanism used to model the Tiger's 102mm(+) mantlet, or by using the same mechanism as the "shot trap" modeling used on Early Panthers and M10s.

While eventually modeling the size and resistance strength of every plate surface would be very nice (and would also open ways to fix other problems like the excessively vulnerable PzIV turret), this degree of detail simply isn't necessary to make this tweak.

Again, too late now, but it certainly could have been done.

Cheers,

YD

[FM Paul Heinrik]

Originally posted by K_Tiger:

I was thinking we discuss advantages/disadvantages from the real ones. In Game therms, the über/ situation from the 80mm Stugs resulted in the fact, that the current CMBB engine cant handle so many different surfaces in one single front armor. So we have to life with the overall 80mm.

Dont underestimate weak spot pennetrations or gun damage, in one of my last CMBB QB i lost all of my 4 JPanthers due to Gun damage in a couple of turns.

Know doubt!! I almost always lose my uber tanks to weak or disabling shots. :mad:

[Mr. Tittles]

Originally posted by lorrin:

The past discussions centered on the following pro and con issues (StuG IIIG and PzKpfw IV generally carry face-hardened armor on front):

A. British firing tests against 32mm/30mm layered (in contact) face-hardened armor on PzKpfw IIIH front with 37mm thru 75mm AP and APCBC results in an effective single plate resistance of 69mm for the two plates.

B. American tests with 37mm thru 90mm APCBC against 30mm/50mm layered (in contact) face-hardened armor on front of PzKpfw IV shows that best test resistance is much greater than a single 80mm plate would provide

C. Standard 76mm APBC from T34 would penetrate about 82mm face-hardened at 100m and 75mm at 500m.

Since StuG IIIG and PzKpfw IVH carried single plate thicknesses of 80mm face-hardened or layered armor with resistance above 80mm, penetrations at 500m should be rare

D. Russians had super hardened, limited availability 76mm APBC round for T34 and field guns that penetrated 90mm face-hardened at 100m and 82mm at 500m, which matches 500m penetration range quoted by JasonC

E. Russians also had solid shot uncapped AP designed to kill Tigers from side, which penetrated about 74mm face-hardened at 500m

F. Upper superstructure armor on StuG IIIG is highly sloped but thin, 50mm at 51 degrees from vertical and 30mm at 68 degrees from vertical, where the thinner plates which might be vulnerable to 76mm APBC at 500m despite large impact angles (APBC is very good against sloped armor due to flat nose, which cancels many of the ricochet forces that plague sharp or rounded nose ammo).

G. Near vertical 30mm/50mm armor on front of StuG IIIG has large bolts and openings through it, is made up of limited size plate and probably would suffer from edge effects on many hits(lowered resistance when hits land near free ends), making it vulnerable to T34 76.2 APBC.

H. Tests and combat results from various sources confirm that 2 pdr AP was not very effective against 32mm/30mm on PzKpfw IIIH front

I. Combat results with 25 pdr AP against PzKpfw IIIH front suggest resistance equal to 62mm face-hardened and maybe more

J. Two homogeneous plates in contact resist penetration with less than the total thickness, because homogeneous armor has less resistance at the surface and there are four surfaces with two plates in contact versus two with one plate.

Two face-hardened armor plates in contact present two separate face-hardened layers which have a total combined thickness greater than a single plate with same overall thickness, first face-hardened layer removes armor piercing cap or blunts uncapped AP reducing effectiveness against second face-hardened layer

K. Germans gave up on 32mm/30mm face-hardened on front of PzKpfw IIIH and went with single 50mm plates on PzKpfw IIIJ, suggesting 32mm/30mm about the same as one 50mm plate. Germans switch from 32mm/30mm because two bolted plates in contact became a maintenance headache, angled hits tended to shear or bend bolts loosening connections

GERMAN RESEARCH

WORLD WAR II

LESLIE E. SIMON

Major General, Ordnance Department

U.S. Army, Retired

Former Director, the Ballistic Research Laboratories

Far more extensive and more fundamental work was done at

TAL during the period 1939-1944. Staff members conducted firing

experiments against both flat and corrugated plate; they

studied the way in which the ogive (the tapering head of the projectile)

broke up and the manner in which the plate was penetrated.

Various types of projectiles with different head shapes

and of different heat treatments, different steels, and different body

lengths were studied. Projectiles were fired both against single

pieces of armor plate and spaced armor plate consisting of two

or three pieces of armor plate with varying spaces between them.

Studies were made both from the viewpoint of the defeat of the

projectile by the armor plate and from the viewpoint of the defeat

of the armor plate by the projectile. They studied the nature of

the entry and the exit of the projectile when the plate was defeated

and of the break-up of the projectile when the projectile was

defeated. The movement and bending of the plate during penetration

were carefully recorded and considered in connection with

the mechanism of penetration.

The use of spaced armor on the decks of battleships for resisting

penetration by armor-piercing bombs was studied in miniature.

The experimental work was carefully correlated with theoretical

work. A theory of penetration was worked out which accounted

for the loss of energy as a function of penetration, and

which gave the force on the projectile, the friction, the force on

the plate, and the effect of ring tension around the projectile as

functions of the distance of penetration. For larger calibers, experimental

and computed values of energy loss agreed to the order

of S or 10 per cent. The results are of value in the design of

fuzes, projectiles, and armor plate. Similar studies were made

on the penetration of safety-glass armor plate by small bullets

with steel cores. The mechanism of breaking in the successive

layers of glass was studied by means of spark cinematographs.

This work was applicable to the glass covers of vision slits in tanks

and combat vehicles.