In the past little while I have read more than several books onn the Bulge.......

............of the dozens out there. Many mentioned both Allied and Axis using AAA of 37-40mm in anti-vehicle as well as personnel roles.. Given the low cloud cover and element of surprise, it makes sense. I assume most if not nearly all such rounds were HE in the Ardenne. Unlike aircraft in anti-tank roles using AP or cored shells. My question is what effect would result in shooting at the various tanks and tank destroyers employed by both sides. I am a novice at tank penetrations by nonconventional ammunition but imagine AAA scant. But would a 37/40mm seriously damage a modern tank of 1944 by perhaps blinding it, jamming turrets, damaging tracts or suspension or any other parts and pieces? The lifetime of a 37/40mm would seem to be short facing numerous adversaries, just like an anti-tank gun. Or could a true tank, medium or up , be penetrated?

I read a rather vivid description of Hitler Jugend manning a quad 20mm and using it on truck born infantry, made me squirm just reading, until a Churchill got it. The scene in SPR between the single 20mm and infantry was equally vivid.

My main interest is between the 37/40 and MBTs and potential ability to disable and/or destroy.. I am aware of planes doing so but am thinking of a trajectory of ground combat of the Ardenne

Gaines

 

Unlikely. For the British, the 40mm SP AAA still in service in December 1944 were relatively few, basically the Crusader AA Mark I, which was used heavily in NEPTUNE, but never expanded beyond that AFAIK. For the US it was the GMC M17 and M17A1 with the 37mm M1 "Colt-Browning" paired with two water-cooled Browning .50 caliber MG mounted on a half track. They were only issued to Antiaircraft Automatic Weapons Battalions (SP), which were usually attached to armored divisions, although they saw other service as well. Engaging a tank with either would be an act of desperation, but if it hit first it could possibly blind the tanks vision systems long enough for the SP AAA to escape...maybe. However, I have found no accounts for that happening in US service and I doubt it happened in Commonwealth service either.

 

Thanks , Richard, all the accounts I have read indicated they were being used in an anti=personnel role and indeed out of necessity. I figured they would only have HE and rather lucky to cause serious damage to a tank....you are no doubt right, to get the hell out of there. An AP shot might do better but then would not likely be on hand. Just curious.

 

US Army tests at Isigny may reveal more of passing/academic interest re M1 40mm. I'm sure there was more detail out there but this is a reasonable summary transcription:
U.S. Army 1944 Firing Test No.2
(Mr Moran does mention the testing here, but, understandably, isn't really concerned with the 40mm results. The Chieftain's Hatch: US Guns, German Armour, Pt 1 )
AP ammunition found to have some effect vs Panther sides and rear at 600yds... but who wants to be within 600 yds of Panthers with a Bofors...
(Personally I wouldn't want to be within 10,000 yards of anything with anything.. but I'm a coward and not fighting for the liberation of humanity.)

No help to the original thought, but beautifully transcribed 40mm manual here for those that like such:
40-mm Automatic Gun M1 (AA)-TM 9-252
(Ammunition types p.258 onwards.)

 

I'm sorry, but you appear to be confusing the Isigny tests of the M1 76mm Gun. Neither the 37mm M1 AA Gun nor the 40mm M1 AA Gun were tested at Isigny.

 

The British had a lot more Light AA than the Crusader 40mm. This was used in Normandy by the 40mm Light AA Batteries in the assault groups landing on D Day. Each troop of six Light AA guns had three Crusader SP 40mm each towing a towed equipment.


There was an unarmoured SP bofors gun that was far more common than the Crusader SP. About one third of the Light AA guns deployed to NW Europe were equipped with the Morris-Commercial C9/B Self-propelled Bofors - developed by the Morris Commerical factory on their own initiative for their own Home Guard.


There was an AP round for the 40mm AA. In Normandy one troop of 110 Light AA Regiment was tasked with supporting the attack on Mount Pincon because the infantry had lost their anti tank guns on hill 112. My father who served in that unit told me he saw this troop as they set off. They these chaps put a brave face on their prospects if they had to face a Tiger tank.

One light AA Regiment - 93rd was equipped with 20mm guns. These were single and triple mounts on towed and Crusader chassis.

I can't find a photo of the equipment but it looked like this

The 20mm guns were mainly withdrawn during Normandy as the Oerlikon ammunition did not destroy themselves at a certain time of flight. They could pose a danger to friendly forces without serious self control; by the gunner.


The 20mm AA gun tanks in armoured regiments ended up in store as the crews were more use as replacements.

However, some Crusader AA Tanks (possibly the 93 Light AA ones) ended up in SP Field artillery regiments as "recce vehicles" and 17 pounder Anti tank units as gun tractors. The 20mm guns weren't going to stop a tank but would make a mess of infantry or light armour and some serious support if the recce party found themselves embarrassed..
.

 

A Bit more. Tony Williams' page has gun datas. The Bofors L60 had an MV abut 50% higher than the 2 Pdr of the same calibre. 37MM AND 40MM GUNS IN BRITISH SERVICE

 

Is that '40mm Gun, M1, AA – AP M58' mentioned in the first transcription something different then?

Is there an error in the document Moran's citing for the July Isigny shoot? (or was it not at Isigny? Hard to think of a better location at that time.)

Quite happy to concede if there is. Grabbed the two from the Internet, but neither seems a particularly dodgy source & both apparently reference the same shoot.



Suspect you're referring to the August Isigny shoot, which was indeed a rather more 76mm & 17pdr affair:
U.S. Army 1944 Firing Test No.3

 

Chris Foss in Artillery of the World 1974 gives the following penetration for the M-1 LAA 40mm @ 900m range penetration of 50mm @ 30º

 

Damn all of you !! I have a project due, people calling, hollowing, screaming and threatening to fire me....if only they would !!

And you chaps plus Richard, no chaps in the US of which I am aware, have supplied me with hours of reading material. Not only getting to my original odd query but nicely expanding on it. . I have never seen a war game in my soon to be 78 years but am greatly appreciative of their making this material easier to find. I have seen a good bit of it, just not so nicely done.

As a 15 year old, I studied ballistics and trajectory charts endlessly as it applied to shoulder arms. I would still love to see WW2 accuracy charts and trajectories but that time may have passed. I saved my money like Silas Marner to buy a Winchester M-70 in 22-250 to conduct but own experiments. Many years passed before I even realized one's made before 1964 were better. I sold it to help pay for school but still miss it

It is just the kid in me that finds all this stuff fascinating. and I genuinely thank all of you for taking time to supply me with serious trivia ( ! ). Plus you have given me a great excuse to not placate the "Keeping up with the Jones" types that are the bain of my existence but also the reason I get to continue my work. I am doing a reinforced concrete safe room at present, tornators what ! But I pretend it is a bunker overlooking Skyline drive !

 

Ah, yes, I see you were referring to the 1st Isigny Test rather than the better known 2d Isigny Test.

 

Some nice footage of Bofors pounding away at ground targets at Goch :

 

If you're looking to waste time here's a fun little program. Unfortunately he didn't add HE penetration. WWII Gun vrs Armour Calculator

 

Damn you, Sir. This thing is neat; there goes my afternoon.

 

There are some equipments missing. I'd like to see penetration figures for the 3" 20cwt and 3.7" AA gun. Both were earmarked as Anti-tank weapons and the Germans seem to have been more worried about the 3.7" as a threat to the Tiger than the 17 Pdr which was the bigger threat.