Tankers talk (Long post)

[fire_ant]

 

Of course the long 75mm on the Panther was still a better AT gun...but the 85mm was a weapon to fear, anyway.

For sure much more than the US 75mm and 76mm.

[/B]

Actually, the us 76mm was more accurate than the 85, had a significantly longer effective range, and only slightly inferior penetration at short range (under 800 yards).  It had better penetration at all ranges in fact when using HVAP ammo.

The only real advantage of the 85mm gun over the US 76 or the German medium velocity 75 (as on the PzIVG or H) was that it was better in HE for use against infantry and soft targets.

The 85 mm was little more use in pentrating the frontal armor on Panthers and Tigers than the US 76mm gun was.  Only the superior maneuvrability, armor strength, speed, and off road performance of the T-34/85 made the big difference.

[Jigster]

 

Originally posted by RAM:
That is what I meant, that the gun contest was levelled. The 85mm gun on the T34/85 and IS85 was a very efficient one compared with the 76mm used in the T34/76. If you put that same gun in a Sherman then there'd been much less problems dealing with german armor.

Of course the long 75mm on the Panther was still a better AT gun...but the 85mm was a weapon to fear, anyway.

For sure much more than the US 75mm and 76mm.

RAM, please remember that slow powder burn only applies to multi-charge guns. Due to the length of the Naval guns, and the fact that 3, 4 or 5 powder bags can't fire off all togather because of design a slow burn is required, starting from the bag closest to the breech and forward to the projectile. The slow burn allows the projectile to accelerate better because the full force of all the charge pushs the projectile before leaving the barrel. However, if a fast burn happened the shell would not recieve as much energy before exiting the barrel, because some powder would not of burned. Shell weight contributes greatly.

Now on single-powder charges, such as a rifle or tank shell, a quick burn is much more desirable because of the much shorter barrels. They are not long enough to yield the same results that long naval barrels with slow-burn powder produce. Mainly this is due to the shell leaving the barrel before the gases from the explosion reach maximum expansion and velocity.

- Jig

[Jigster]

 

Originally posted by fire_ant:
Fascinating post Pyro.

I notice a few things which could be inferred however...

The main complaints against German tanks were against the Mk V (Panther) and Mk VI (Tiger) tanks, not the Mk IV modeled in this game.  In fact, against an M4A3E8 or "easy 8" the Mk IVG or H is roughly equal, actually slight inferior, and Mk IV F2 on down are inferior.  The 75mm gun on the Mk IV is equivalent to the US 76mm gun, inferior to it if the Americans have HVAP ammunition available.  

Tactically, the M4A3E8 has better armor by about 30%, the same gun, more ammo, better traverse, is faster (about 15 mph vs 12 mph cross country)has more and better machine guns, and a gyrostabiliser (though only about 1/2 of tank crews were able to get these to work).  The Pz IVG or H has a lower silhouette (which is actually a very big deal in tank warfare), better optics, and often was fitted with extra protection against HEAT (i.e. bazooka) warheads in the form of plates mounted about 12-16" off the side of the tank.

For this game though to start I would reccomend the T-34/76C.  It has better armor than the Pz IV, is almost twice as fast, but has an inferior gun (A low velocity 76 versus a medium velocity 75 on the Pz).  This should introduce some interesting situations.  The fact that unlike most tanks the T-34 also had nearly as thick side armor as front armor, it should be able to maneuver closer to a Pz IV with some success, and due to the inferior armor on the Pz they both reach each others lethal range (about 1,000 yards) at about the same time.

Finally I think a lot of the favorable commentary on the chaffee in that doc was due to it's recent appearance at that time.  It had a low velocity 75mm gun which was the equivalent of the original M4.  It may be interesting to note however that the M24 Chaffee fared poorly in the Korean war when faced with Russian made tanks (as did, to a lesser extent the M4A3E8 and the Pershing...)

DB

HVAP ammo is really not an option, normally the only tanks that carried them were the platoon commander's tank. He also carried the smoke shells most of the time.

The US 76mm is by no means better then the 75 Pak on the Panzer IVH. Luckily the Panzer IVH is realtively thin-skinned so even the US 75mm has a good chance of killing it, even with a frontal shot.

- Jig

[Jigster]

 

Originally posted by fire_ant:
Actually, the us 76mm was more accurate than the 85, had a significantly longer effective range, and only slightly inferior penetration at short range (under 800 yards).  It had better penetration at all ranges in fact when using HVAP ammo.

The only real advantage of the 85mm gun over the US 76 or the German medium velocity 75 (as on the PzIVG or H) was that it was better in HE for use against infantry and soft targets.

The 85 mm was little more use in pentrating the frontal armor on Panthers and Tigers than the US 76mm gun was.  Only the superior maneuvrability, armor strength, speed, and off road performance of the T-34/85 made the big difference.

Hmmm. The Soviet 85 mm with less penetration power then the US 76mm...Considering in normal APCBC rounds the 85 has the same muzzle velocity and weighs 2 kgs more...I don't see how that's possible. The 85mm is equal to the PzVI's 88.

HVAP ammo was not a widely used thing by the US Army...while it can be argued that APCBC rounds aren't the best AT rounds that were avaiable, every tank that served in WWII carried some sort, and I use them to make basic gun penetration comparisons.

- Jig

[RAM]

 

Originally posted by Jigster:
. Due to the length of the Naval guns, and the fact that 3, 4 or 5 powder bags can't fire off all togather because of design a slow burn is required, starting from the bag closest to the breech and forward to the projectile

Yes and no. Yes, that compared with AT roudns the powder is slow burning, but no in that US navy used a VERY SLOW burning powder in their naval guns. THe italians used the faster burning in their 15inch guns (thats why they needed a reboring each 100 rounds fired,and why they had so long range-and bad accuracy-)

I'm not saying they used the same powder in Naval guns and AT guns, my god   I say that its curious how smart were the designers on one branch of the militar machine and how stupid were the other branch's designers.And that is curious the contrast between them   Nothing else  

[RAM]

 

Originally posted by fire_ant:
Actually, the us 76mm was more accurate than the 85, had a significantly longer effective range, and only slightly inferior penetration at short range (under 800 yards).  It had better penetration at all ranges in fact when using HVAP ammo.

Every one and each of the sources I've read say that the 85mm had the same muzzle velocity than the US 76.2mm, and that it fired a 9Kg round while the US one was some 7kg (talking by memory here, sorry). That leads to a better penetration and equal accuracy OF THE GUN. Of course Soviet optics industry was lacking ,to say the least,compared with the US optics (and not talking about germans, as they were better than the allies fielded during WWII).

 That would make the 85mm gun harder to aim, and may have lead you to say that the gun itself had less accurate,but it had nothing to do with the gun, but with the optics involved.

About the HVAP ammo...well the germans had,too, tungsten cored AP rounds...of course tungsten was a war critical material and there weren't very common (in fact they were extremely rare)...same happens with HVAP...

For me the penetration of a gun its marked by the most common round used with it...so HVAP are out of question here,at least for comparing guns.




[This message has been edited by RAM (edited 07-31-2000).]

[Pongo]

Not really much use in debating what might be the relitive capabilities of the different guns. The numbers are quite well documented.
By recollection the US 76 L53 is very slightly better then the Soviet 85 L51.5 which is very slightly better then the German 75 L48. With out special ammo they are near equivilent. With Special ammo available the US 76 pulls ahead a little and the German  takes the lead from the soviet 85
Anyway. The soviet 85mm L51 should not be considered equivilent to the German 88mmL56. It is much more closely matched with the 75mmL48.

[fire_ant]

 

Originally posted by Jigster:
Hmmm. The Soviet 85 mm with less penetration power then the US 76mm...Considering in normal APCBC rounds the 85 has the same muzzle velocity and weighs 2 kgs more...I don't see how that's possible. The 85mm is equal to the PzVI's 88.

HVAP ammo was not a widely used thing by the US Army...while it can be argued that APCBC rounds aren't the best AT rounds that were avaiable, every tank that served in WWII carried some sort, and I use them to make basic gun penetration comparisons.

- Jig

After reading your rebuttal of my facts, I considered that most of my knowlege of this is based on playing Advanced Squad Leader back when I was a youngster more than six or seven years ago.  So I did some research to confirm my figures and found an excellent website at http://www.wargamer.org/GvA/  which seems to have definitvie information on tank gun and tank armor peformance.  I compiled some comparisons of the guns found on the T34/85, the M4A3/76, and the latest model Pz IV's, which you may see below:

Penetration of a 30 degree sloped armor plate:

Gun      ammo      500 meters      1000 meters      2000 meters

Soviet

T34/85 (zis53) AP      90mm         75mm         65mm   
85mm / L53   APBC      90mm         85mm         70mm
      APCR      100mm      80mm         *


German

Kw K.40
75mm / L43   APBC      91mm         81mm         63mm
      APDS      108mm      97mm         *

75mm / L48   APBC      96mm         85mm         64mm
      APDS      120mm      97mm         *

US
(US calculations were made in yards so the comparison is not quite exact)

            457 meters      914 meters      1828 meters

M1 76 series   AP      109mm      76mm         64mm
76mm / L55   APBC      93mm         88mm         75mm            APCR (hvap)   157mm      116mm      98mm

·   = indicates weapon did not reach that range with that ammo type

I think the data shows the US 76mm gun was comparable to, in fact probably slightly better than both the Zis – 53 85mm gun of the T34/85 and the Kwk 40 (both versions) on the Pz IVG and H.  It is without a doubt markedly superior when using HVAP ammo.

Incidentally, 8-10 rounds of HVAP ammo was usually available to most Tank Destroyers (M10, M18, and M36 /90mm) by December of 1944 (Battle of the Bulge) and 3-5 rounds were usually deployed on 76mm caliber M4 Tanks as well, not just the command vehicle… (in fact a lot of times the command vehicle was a M4 with a 75mm gun) HVAP was not plentiful but it was not at all uncommon, there was usually enough for each 76mm armed tank or TD to fire a few rounds at that first Tiger or Panther to appear.  If they were lucky enough to engage inside 2,000 yards or so that is!  If they were sighted by Pz V or Pz VI at 3,000 or 3,500 yards US tanks were offensively helpless!  (so was a T34, but at least a t34 charge would get into range almost twice as fast due to it's excellent speed and cross country mobility)
On the other hand HVAP would not be necessary against the Pz IV at most ranges.
It might also be worthwhile noting that HVAP was less accurate than normal AP ammo.

Just for giggles I looked up some of the armor values too…

Armor      Hull Front   Hull Sides      Turret Front      Turret Sides

T-34C      45mm/60   45mm/40      52mm   (round)      52mm/30
T-34/85   45mm/60   45mm/40      90mm   (round)      75mm
Pz IVH   50mm/9   30mm (+5*)/0      50mm/10      30mm/25
M4      64mm/47   38mm/0      76mm/30      51mm/5
M4A3E8   64mm/47   38mm/0      89mm/ (round)   64mm/13

The number after the slash is the degrees of slope.  I’m not sure what the precise formula is for determining how slope effects penetration but I do know that 45 degree of slope effectively doubles the thickness of the armor.  You can see this if you turn a 1” thick book or box 45 degrees, and then measure the width across a horizontal plane.  

The asterix represents the “shurzen”, i.e. special anti-bazooka armor fitted to many Pz IV’s

[Jigster]

 

Originally posted by Pongo:
Not really much use in debating what might be the relitive capabilities of the different guns. The numbers are quite well documented.
By recollection the US 76 L53 is very slightly better then the Soviet 85 L51.5 which is very slightly better then the German 75 L48. With out special ammo they are near equivilent. With Special ammo available the US 76 pulls ahead a little and the German  takes the lead from the soviet 85
Anyway. The soviet 85mm L51 should not be considered equivilent to the German 88mmL56. It is much more closely matched with the 75mmL48.

In APCBC rounds :

German 88L56 :
projectile muzzle velocity:  773 m/s
projectile mass (penetration portion only): 10.2 kg

US 76L53 :
projectile muzzle velocity:  792 m/s
projectile mass (penetration portion only): 7.0 kg

Soviet 85L51 :
projectile muzzle velocity:  792 m/s
projectile mass (penetration portion only): 9.02 kg

German 75L48 :
projectile muzzle velocity:  790 m/s
projectile mass (penetration portion only): 6.8 kg

German 75L70 :
projectile muzzle velocity:  925 m/s
projectile mass (penetration portion only): 6.8 kg

German 88 kwk :
projectile muzzle velocity:  1000 m/s
projectile mass (penetration portion only): 10.8 kg

As I said before APCBC are not the best preforming AP rounds, but they are about the only ones that a comparison can be made with.

And ant, yes they were issued HVAP...normally 4 rounds. But they did not get more for very long periods of time. Such as in the Adrennes, after the stuggle began most tank crews only got APCBC and few HE shells during the night, due to the supplies just not being there. So for about eight days they were fighting PzIV's, PzV's, Stugs, and PzVI's with only standard APCBC ammo. Sadly for the American tank crews situations like this were the rule, not the exception.

- Jig

[Jigster]

 

Originally posted by RAM:

Originally posted by Jigster:
. Due to the length of the Naval guns, and the fact that 3, 4 or 5 powder bags can't fire off all togather because of design a slow burn is required, starting from the bag closest to the breech and forward to the projectile

Yes and no. Yes, that compared with AT roudns the powder is slow burning, but no in that US navy used a VERY SLOW burning powder in their naval guns. THe italians used the faster burning in their 15inch guns (thats why they needed a reboring each 100 rounds fired,and why they had so long range-and bad accuracy-)

I'm not saying they used the same powder in Naval guns and AT guns, my god   (Image removed from quote.) I say that its curious how smart were the designers on one branch of the militar machine and how stupid were the other branch's designers.And that is curious the contrast between them   (Image removed from quote.) Nothing else   (Image removed from quote.)[/B]

I bet a few of the naval powder bags inside a nice metal container would make one heck of a bomb...I mean look what happened when they over-rammed in the Missouri!.

- Jig

[RAM]

   

Originally posted by Jigster:

I bet a few of the naval powder bags inside a nice metal container would make one heck of a bomb...I mean look what happened when they over-rammed in the Missouri!.

- Jig

LOL Jig the slow burning powder is a relative thing, compared with other countries' powder, the US navy used a very slow burning one...that doesnt mean that you can play with that powder as it was a soccer ball!  

Uh, yeah, #2 turret on Missouri blew up after that "incident"...you need to be cautious when you add the propellant for a 2700lbs round into a gun!!!  

(BTW there is some debate about the blewing up of the HMS Hood, there is a theory that explains the magazine explosion as a chain reaction after the blewing of a overrammed round in a turret...read of it a while ago, dont remember the details, but as a theory, it exists)


[This message has been edited by RAM (edited 08-01-2000).]

[fire_ant]

 

Originally posted by Jigster:
In APCBC rounds :

US 76L53 :
projectile muzzle velocity:  792 m/s
projectile mass (penetration portion only): 7.0 kg

Soviet 85L51 :
projectile muzzle velocity:  792 m/s
projectile mass (penetration portion only): 9.02 kg

German 75L48 :
projectile muzzle velocity:  790 m/s
projectile mass (penetration portion only): 6.8 kg


The muzzle veloctiy and mass is irrelevant, though interesting from a ballistic perspective.  Despite the weight of the 85, the pennetration tables clearly prove that you were wrong in your assumption.  The US 76mm gun, using all types of ammunition, was slightly superior at penetration to both the 85mm and the German 75/43 and 75/48 guns used in the late model Pz IV's.


As I said before APCBC are not the best preforming AP rounds, but they are about the only ones that a comparison can be made with.


I don't find any reason to agree with this statement... By the end of wwII until today either APDS or 'Hvap' type ammunition with a sub calibre core of high density material was and is the standard AP ammunition.  


And ant, yes they were issued HVAP...normally 4 rounds. But they did not get more for very long periods of time. Such as in the Adrennes, after the stuggle began most tank crews only got APCBC and few HE shells during the night, due to the supplies just not being there. So for about eight days they were fighting PzIV's, PzV's, Stugs, and PzVI's with only standard APCBC ammo. Sadly for the American tank crews situations like this were the rule, not the exception.


As far as I have read, whenever ammunition was issued there was usually some percentage of HVAP, and they usually had 8 or ten for TD's and 3 or 4 for 76mm armed Tanks.  Proving this would probably be more trouble than it's worth though so we can agree to disagree...
- Jig

[/B]

[Hamish]

Just as a comment on the overall picture of this thread, I think that something has been overlooked. Obviously with this wealth of information you posted Pyro, you have been doing some serious research into WW2 tanks, thier comparative strengths/weaknesses and how they matched up against each other. Can we take this to mean you have an idea as to what tank/vehicles are in our future in the AH community? I ask this just out of curiosity as I am mainly a fighter jock, but i like driving around in the mud every now and again for a change of pace  

Very deep reading btw, and a very interesting look into what our commanders/GI's were thinking back in the war, Thanks for posting it, and keep up the great work. I am suprised every day by AH, and am never dissappointed in the work you guys are doing.

<S>

Hamish

 

Man i love Milenko's Noseart  

[This message has been edited by Hamish (edited 08-01-2000).]

[dosequis]

Well, I've been playing Combat Mission alot, and I need to post these messages to the BBS over there. Because, IMHO, the M4 is overmodelled in CM.

I'm reading here that Panthers were essentially unassailable by the M4 at ranges of 1500m or better. That is not the case in CM. Tigers with the AP 88 should be practically invincible at 2000m+ hull down, and again I have seen in CM troops abandon the Tiger I when being fired on by a Firefly at 2500m!!!!!!!!

I like CM, and I just got the new patch, but play it for awhile and you come to realize that in many of these scenarios, they pitch you into spots where the lay of the land makes it really hard to fight at optimal German ranges. When the guy in Pyro's post says, "The Germans never let us get that close" it frustrates me because some of the CM scenarios thrust German armor in WAY too close. And the AI moves it forward, but that's another gripe.

XX

[Paul L]

I think you people need to see the Russian info on the 85mm gun, while the penetration is listed as 90mm @ 30° @ 500 meters.  This is the 80% penetration mark and the 50% ballistic limit value should be ~ 10% higher....or 99mm @ 30° at 500 m

But we're left with a question what hardness are the projectiles tested on I bet there all different.

[URL]http://www.history.enjoy.ru/guns/defin_4.html[URL]