Pak 97/38 vs M1897A4

[sturmovik]

I just noticed the penetration values for what in essence should be the same weapon on different sides of the Atlantic were very different. I was unsuccessful with a Google search to find penetration values for the M1897A4 gun, which was the type mounted on the M3 75mm GMC so I was wondering if anyone here had some numbers for it.

The current values in the OB's are 50mm AP and 70mm Sabot compared with a single 80mm AP rating for the axis-used French weapons.

[DRG]

There are some discrepancies with these weapons. ( see attached ) I've put it on the list to look into, The ap difference would have come from various sources giving an AP rating for the weapons as used by allies and the Axis. Perhaps someone knows if there was a significant difference in the way the AP that was used by the two sides was manuafactured that could account for the differing penetration data

Don

[Cross]

There's a 1944 US Army document declassified in 1958 that appears to give penetration for this weapon. Go to page 22 (page 166 of the original document):

http://www.scribd.com/doc/13810712/S...log-1944-Vol-2

It's difficult to read, and you'll have to zoom in, but if I'm reading it correctly (not sure that I am) it gives this penetration (homogeneous plate) at 20 degrees:


............AP......APC
500yds....81......71mm
1000yds...69......64mm
2000yds...53......53mm


Hope this helps,
Cross

[DRG]

76 mm of armour at 20 degrees would be the same as 81 at zero inclination. In game terms to recreate that AP - APC result at 500 yards the AP would need to be a 8 or 9 pen which is the same as the PaK 97. It's on the list to investigate

[sturmovik]

Thanks. Not trying to be a nitpick here, but I am editing my set of custom OBs and as issues arise I am posting them.

[cbo]

According to Hunnicutt: "Halftrack....", the 75mm M1987A4 managed

APC M61
500 yards: 64mm
1000 yards: 58mm
1500 yards: 52mm
2000 yards: 48mm

AP M72
500 yards: 74mm
1000 yards: 61mm
1500 yards: 48mm
2000 yards: 38mm

all vs homogenous armour at 30 degrees.

Figures for the 7,5cm PaK 97/38 from varous German books suggest

Polish AP? (armour type and angle unknown)
500m: 58mm

Polish AP? (armour type and angle unknown)
100m: 61mm
1000m: 58mm

Seems pretty much in the same ballpark to me. The US M72 round was an uncapped monobloc rounds with no HE filler and would probably be a bit more robust during penetration than rounds with an HE filler. The M61 was a capped round with HE filler. No idea about the Polish one.


David Lehmann, who usually have his sources in order quotes the following for french AP ammunition fired from the 75mm L/34.5 Mle1897/33

Obus de rupture Mle1910M (AP/HE) (0 degree impact, armour type unknown)
100m: 71.5mm
500m: 61.5mm

Obus perforant AL (Allongé Lefèvre) Mle 1916 (AP/HE) (30 degrees, armour type unknown)
400m: 40mm

Obus perforant AL (Allongé Lefèvre) Mle 1918 (AP/HE)(30 degrees, armour type unknown)
400m: 40mm

A usual, different testing conditions and criteria may apply and could screw up any meaningfull comparison

cbo

[DRG]

Thanks Claus. I'll add this to the to-do and look at it when I get to it

Don