75mm German, US and composite AP shots and shells

[Juha Tompuri]

Splitted from:
http://forum.axishistory.com/viewtopic. ... 0#p1998391

The Gr. Rot is the hollow-charge? In that case that's probably neither here nor there in this context?

APCBC-HE (armor piercing capped ballisict capped high explosive. Possibly also -T for tracer)
IIRC, this is the same shell British also worked to fit their Grant tanks? For some unknown reason.

Regards, Juha

[Urmel]

Ah okay. That would explain the lacklustre AP performance I guess.

Reason for trying to get it into the Grants was a supply issue of US-built 75mm. There's a thread somewhere in the Middle East section.

[Juha Tompuri]

Ah okay. That would explain the lacklustre AP performance I guess.

Reason for trying to get it into the Grants was a supply issue of US-built 75mm.

Interesting.
This site mentions the things differently.
Hints towards APHE performance issue, but of a bit different type than you mentioned.

The first 75mm cannon mounted on German tanks and assault guns was the short 75mm/L24 cannon. The armor piercing (AP) shell was the Panzer Kannon Grenade with red band (K.Gr rot Pz.). The shell had a large (by German standards) cavity for an explosive charge of 80 grams. In North Africa a quantity of these shells were captured by the British and subjected to testing. The Cairo tests during March 1942 showed that penetration of tank armor by the German 75mm AP shell caused a disastrous burst effect inside the tank. It was decided that thousands of captured German 75mm AP shells were to be converted to be fired by US 75mm guns.

http://www.panzer-war.com/page43.html

The above mentioned Cairo test


Regards, Juha

[Richard Anderson]

The reason for the field-expedient 75mm APC for the Medium Tank M3 in North Africa was fairly simple. The German tanks initially encountered in the Western Desert were the Panzer III and Panzer IV, which made use of face-hardened armor or face-hardened reinforcing plates. Unfortunately, effective penetration of face-hardened armor required a projectile with a piercing cap, which absorbed the shock of impact and prevented deformation or shattering of the projectile body when it struck. However, production of such a round for the M2 and M3 75mm Gun in the M3 and M4 Medium tanks – APC M61 – did not begin until January 1942 and was not delivered to British forces until after the Gazala battles in spring 1942. As a consequence, initially only AP M72 was available, a simple mono-bloc armor piercing round, which when tested against captured German tanks near Cairo in March 1942 was found to be relatively ineffective at ranges over 500 yards. An expedient was invented by an Australian officer, Major Northy, who mated captured German 75mm APC projectiles to American cartridge cases with enthusiastic support from an American Ordnance officer, Major G. B. Jarret. Hunnicutt, Sherman, p. 89.

APHE was preferred by the American forces over AP, but in this case the reasoning was the better performance of the capped round versus face-hardened armor. Ironically, later the opposite proved true, the capped APHE rounds like the 75mm M61 and the 76mm M62 turned out to have poor performance against the highly-sloped homogeneous armor of the Panther, partly because of premature operation of the HE fuzing on impact.

[Juha Tompuri]

Thank you Richard for clearing up things.

Regards, Juha

[Juha Tompuri]

... enthusiastic support from an American Ordnance officer, Major G. B. Jarret

His name pops up at several reports I have read about artillery and ammunition at WWII era North Africa.

Regards, Juha

[Richard Anderson]

... enthusiastic support from an American Ordnance officer, Major G. B. Jarret

His name pops up at several reports I have read about artillery and ammunition at WWII era North Africa.

Regards, Juha

He and Major (later Colonel) Robert Icks were two of the better known Ordnance officers of the war. Jarrett was responsible postwar for creating the Aberdeen Proving Ground Ordnance Museum despite Army indifference (unlike the US Marine Corps, the US Army rarely exhibits much interest in any form of history, even its own). Jarret spent much of 1942 in North Africa as head of the US Army Ordnance liaison mission.

[LineDoggie]

... enthusiastic support from an American Ordnance officer, Major G. B. Jarret

His name pops up at several reports I have read about artillery and ammunition at WWII era North Africa.

Regards, Juha

He and Major (later Colonel) Robert Icks were two of the better known Ordnance officers of the war. Jarrett was responsible postwar for creating the Aberdeen Proving Ground Ordnance Museum despite Army indifference (unlike the US Marine Corps, the US Army rarely exhibits much interest in any form of history, even its own). Jarret spent much of 1942 in North Africa as head of the US Army Ordnance liaison mission.

Maj. Jarrett apparently had an extensive personal collection of WW1 Arms and ordnance he collected while touring the battlefield after the war. He had a Museum of his own that made the press of the 30's. Small Arms review did a story on him that was pretty interesting. He enlisted in 1927

http://smallarmsoftheworld.com/display. ... ticles=269

[Juha Tompuri]

Thanks LineDoggie,

Very interesting article and site.
By Small Arms review search function a lot more articles and photos about him

George Burling Jarrett
"The Junkman who stopped Rommel"

[David W]

Hello Richard.

I know that it is a bit arbitrary, but do you know of any penetration figures that illustrate the difference between AP M72 & APC M61?

Thanks,
David.

[Richard Anderson]

Hello Richard.

I know that it is a bit arbitrary, but do you know of any penetration figures that illustrate the difference between AP M72 & APC M61?

Thanks,
David.

I would consult Terminal Ballistics.

[David W]

Thanks.

I'll try a search tonight.

[Juha Tompuri]

APC M61?

Did the M61 also have a ballistic cap?
At the a little blurry text at Cairo test report it is mentioned that the M61 was fired "less bursting charge". So was it originally a APC(BC?)-HE(tracer)? If so when, why and by who the HE was removed from that shell, and was the HE replaced by some other material?

Regards, Juha

[Richard Anderson]

APC M61?

Did the M61 also have a ballistic cap?
At the a little blurry text at Cairo test report it is mentioned that the M61 was fired "less bursting charge". So was it originally a APC(BC?)-HE(tracer)? If so when, why and by who the HE was removed from that shell, and was the HE replaced by some other material?

Regards, Juha

The US Army Ordnance enjoyed giving ambiguous designations. The 75mm M61 APC-T round was a capped armored piercing penetrator with a ballistic cap, an HE burster and fuze, and a tracer element. Technically it was APHECBC-T.

76mm M62 APC-T was the same.

75mm M72 AP-T was a solid AP projectile with a tracer element and no penetrating or ballistic cap. 76mm M79 AP-T was the same.

[Juha Tompuri]

Thanks,

So, the M61 at the "Cairo test" was of a similar design as the "hybrid" K.Gr.rot.Pz shell, but with lesser after armour effects, because of being fired as a non-HE shot?

Regards, Juha