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76Mm M32 Gun Penetration


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#1 Nikolas93TS

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Posted 29 June 2017 - 2039 PM

I was wondering if any new information emerged in the last 3-4 years on penetration capabilities of M339 APBC, M319 APCR and M331 APDS?

 

Hunnicutt didn't list any values because it was still classified at the time, but since then those rounds felt into oblivion. Is there at least a way to approximately calculate the penetration like for long rods?



#2 Ken Estes

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Posted 30 June 2017 - 0302 AM

This was published in an armor conference at Detroit Tank Plant in 1949, showing HVAP/APCR expectations at the time. Not what you asked for but perhaps relevant.

 

scan10001wt3.jpg



#3 bojan

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Posted 30 June 2017 - 0628 AM

Was the HVAP for 120mm M58 gun ever issued?



#4 Ken Estes

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Posted 30 June 2017 - 0803 AM

No it was not, Bojan, and neither was the APDS, which as I recall was only developed later in a British effort for the Conqueror, as told by Rob Griffin in his book on the same. The US Army lost interest in the 120mm and heavy tanks in general at the same time (1958) it was completing the upgrades to deliver the 220 M103A1 to the USMC. The army completed development and improvements for the 120mm HEAT and APC and as you know, the army trusted in HEAT for penetrating heavy armor until sometime in the 1960s, especially after the 1967 Israeli conflict. The last 120mm HEAT was the T153E15 at the end of the service life of the M103. APC was doing so well against sloped armor that the HVAP 120mm project was discarded around 1957-58 as well.



#5 bojan

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Posted 30 June 2017 - 0914 AM

...APC was doing so well against sloped armor that the HVAP 120mm project was discarded around 1957-58 as well.

Hunnicutt gives 124mm@60deg@1000yards and 114mm@60deg@1000yards, so that (and a same gun on Conqueror) was only western weapon that could reliably penetrate T-54 glacis @ 2000 yards*, and one of few that could do it @ 1000 until 105mm got introduced. It was a bit iffy for Soviet heavies**, but those would struggle vs M103 also. HVAP was horrible at high angles anyway, so totally reasonable it was abandoned.

 

*excluding HEAT.

 

**If the HEAT fusing worked at large angles it would easily deal with Soviet heavies, but that is big if considering problems with fusing on practically every other US HEAT of the period.


Edited by bojan, 30 June 2017 - 0917 AM.


#6 Nikolas93TS

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Posted 30 June 2017 - 0920 AM

Might it also mean M319 APCR was not widely issued, or replaced by M331 APDS? If I remember well, APCR for 90mm gun on M48A3 was also discontinued after some time because of excessive bore wear.



#7 Ken Estes

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Posted 30 June 2017 - 1055 AM

In the case of the 90mm tank cannon, the shift to the M36/M41 gun also saw the max chamber pressure at 47,000 psi, compared to the earlier 38,000 of the M3/M3A guns. This allowed the APC to perform as well [and better on slopes] than the APCR. Because of bore wear, it was not issued and in the M48A3s of the Vietnam period, there were no cams in the ballistic computer for APCR, nor did any of my experienced NCOs know of it in service after the Korean War.

 

Thus, I don't think 90mm APCR was issued after the M47, but we on TN have lost our last M48A1 soldier, Old Tanker [Ron Seeley] who had posted on this years back. 



#8 RoflSeal

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Posted 02 July 2017 - 1249 PM

This screenshot has been on the War Thunder forums in various bug reports by Conraire on the under performing US guns in the game

It is from "Armament for Future tanks or similar combat vehicles", from 1958.

Spoiler

 

76mm M319/T66 HVAP-T From 76mm Gun M32

 

From Document armament for future tanks or similar combat vehicles.

76mm M319/T66e4 HVAP-T @ 4125ft/s
Angle  1000yd    2000yd
         210mm    160mm
30°       167mm    119mm
55°         68mm      48mm
60°         58mm      38mm

 

76mm M331A2 HV-APDS-T From 76mm Gun M32

 

From Document armament for future tanks or similar combat vehicles.

76mm M331A2 HVAPDS-T @ 4125ft/s
Angle       1000yd      2000yd
0/90°         261mm      231mm
30/60°       193mm      170mm
55/35°         94mm        78mm
60/30°         73mm        61mm

 

 

There is also this document

http://www.dtic.mil/...t/u2/301343.pdf

That contains penetration data for the M32, among other guns as well.



#9 bojan

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Posted 02 July 2017 - 1517 PM

Was M331A2 APDS ever used by US? Interesting that it really suffers from angle which is indicative of the first generation APDS and HVAP - at 60deg it penetrates only 73mm instead of theoretical 130 - which is only 56% of theoretical performances...


Edited by bojan, 02 July 2017 - 1820 PM.


#10 Nikolas93TS

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Posted 02 July 2017 - 1656 PM

Thanks, RoflSeal, those are extremely interesting documents and definitively groundbreaking for me.

 

Was M331A2 APFSDS ever used by US? Interesting that it really suffers from angle which is indicative of the first generation APDS and HVAP - at 60deg it penetrates only 73mm instead of theoretical 130 - which is only 56% of theoretical performances...

 

I thought HVAP-DS was American term for what we can most closely define as APDS rather than APFSDS. Like HVAP and APCR. 



#11 RoflSeal

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Posted 02 July 2017 - 1811 PM

Was M331A2 APFSDS ever used by US? Interesting that it really suffers from angle which is indicative of the first generation APDS and HVAP - at 60deg it penetrates only 73mm instead of theoretical 130 - which is only 56% of theoretical performances...

M331 is APDS.

M464 is the APFSDS developed for this gun, IIRC never used by the US, but definately by countries like Taiwan



#12 bojan

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Posted 02 July 2017 - 1820 PM

 

I thought HVAP-DS was American term for what we can most closely define as APDS rather than APFSDS. Like HVAP and APCR. 

Yes, my typo, edited now.


Edited by bojan, 02 July 2017 - 1820 PM.





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