WW II Ballistics Tank Gun Penetration - France

I haven't found a French penetration criteria   I also haven't seen any proper firing tables or ballistic graphs.   There are often only single points of penetration at range.  Most firing tables must use the ballistics to compute penetration at ranges.  Since none of this exists I will use the ballistics of similar shell of other known guns.  Together with known data like weight and muzzle velocity I use the NaaB2 program to generate firing tables for guns of 37mm and greater.  So the following data is calculated using Nathan Okun's HCWCALC formula.and Robert McCoy's ballistics.   This checked against the few data points available.

Gun ballistic models come from US 37mm AP, APC and APCBC shell models.  US 57mm AP and APCBC shell models.   US 75mm AP and APCBC-HE shell models.

Armor Basis is Averaged and Normalized to RHA BHN 270
Penetration figures use 50% success criteria.
Gun TypeAmmunitionAngleMuzzle velocity Penetration (mm)
100 m300 m500 m1000 m1500 m2000 m2500 m3000 m
25mm/L72 SA mle 34 AP 880 m/s (2887 ft/s) 47 42 37 22 15
25mm/L77 SA mle37 Antichar AP 918 m/s (3012 ft/s) 50 45 40 28 21
37mm/L21 SA18APHE 388 m/s (1273 ft/s) 15 13 12 10
37mm/L21 SA18AP 388 m/s (1273 ft/s) 16 14 13 11
37mm/L21 SA18 mle35APCR 600 m/s (1969 ft/s) 34 28 23 14
37mm/L33 SA38APC 600 m/s (1969 ft/s) 26 20 15 11 10
37mm/L33 SA38APC 705 m/s (2313 ft/s) 40 33 27 17 15
47mm/L30 SA34APHE 450 m/s (1476 ft/s) 33 29 25 21 18 16
47mm/L32.1 SA35APC 660 m/s (2165 ft/s) 50 46 42 32 24 18
47mm/L53 SA37 AnticharAPCBC 855 m/s (2805 ft/s) 75 71 67 57 48 39
75mm/L9.5 Blockhaus SchneiderHE 200 m/s ( 656 ft/s) 13 12 12 12
75mm/L17.1 SA-35APHE 220 m/s ( 722 ft/s) 21 21 21 19 18
75mm/L17.1 SA-35 (*)APHE 387 m/s (1270 ft/s) 47 44 41 35 33
75mm/L36 Modèle1897APHE 500 m/s (1640 ft/s) 66 63 60 49 41 36

There is a very large difference between the French data on the performance of the 47mm/L53 and the German data.  The penetration according to France is more than 40% higher than the German evaluation.  For example according to the French Ministry of Defense the shot should penetrate 89mm @ 0° @ 500m.   But the German data gives it only 50mm @ 30° @ 500m.  This is a solid shot with a thin AP cap.  So would not be a weak shell unless it shattered on thick armor.  The penetration data here is the average of both German and generated data.

There's a question of the muzzle velocity of the 75mm/L17.1.  A couple of sites have it as 475 m/s.   Which seems exceedingly high given it's shortness.  This may have come from some German records.   But, a French site has it as 220 m/s.  Second French site.    If anyone should know it is the French.   If you don't believe those check out the  7:42 on Chieftains video.

(*)  If the muzzle velocity was 387 m/s the penetration values will at least match that which one documentation says it is of 40mm @30°  @ 400m.  (US Class 'B' armor.)

WW II Ballistics Tank Gun Penetration - Italy

Armor Basis is Averaged and Normalized to RHA BHN 270
Penetration figures use 50% success criteria.
Gun TypeAmmunitionAngleMuzzle velocity Penetration (mm)
100 m300 m500 m1000 m1500 m2000 m2500 m3000 m
20mm/L65 Breda M35AP 840 m/s (2756 ft/s) 36 30 24 16 7
37mm/L40 AP 690 m/s (2264 ft/s) 50 43 36 23 16 14
37mm/L40 APHE 690 m/s (2264 ft/s) 46 45 43 37 30 24
47mm/L32 M35APHE 630 m/s (2067 ft/s) 52 49 45 33 24 21
47mm/L32 M35APBCHE 630 m/s (2067 ft/s) 46 45 43 37 30 24
47mm/L40 M39APBCHE 820 m/s (2690 ft/s) 66 63 61 53 46 39
47mm/L40 M39effetto-pronto 310 m/s (1017 ft/s) 44 44 44 44
65mm/L17 effetto-pronto 345 m/s (1132 ft/s) 62 62 62 62
75mm/L18 M34APCBCHE 450 m/s (1476 ft/s) 52 49 47 41 35 32
75mm/L18 M34E.P. 450 m/s (1476 ft/s) 72 72 72 72
75mm/L28.4 M11APCBCHE 502 m/s (1647 ft/s) 57 55 53 47 40 35
75mm/L34 M37APCBCHE 637 m/s (2090 ft/s) 83 80 76 68 60 52
75mm/L34 M37E.P.S. 500 m/s (1640 ft/s) 85 85 85 85
75mm/L46 M34APCBCHE 750 m/s (2461 ft/s) 107102 98 88 77 68 60
90mm/L53 M41APCBCHE 850 m/s (2789 ft/s) 155150146133121110100 90
100mm/17E.P.S. 407 m/s (1335 ft/s) 107107107107
105mm/28E.P.S. 565 m/s (1854 ft/s) 107107107107

The above is a calculated firing table using NaaB2.  In it I am assuming that the projectiles have soft AP caps.  37mm and greater generated by formula in HCWCALC STS Armor Penetration Calculation Program.  A reminder is that this program uses a M79APCLC as a basis.  It is calibrated from the US M79 solid steel projectile.  It assumed it is perfect and indestructible. Thus would have a shell quality of 1.0.   From there HCWCALC introduces energy loss due to AP cap and windscreen destruction. This would reduce the Ballistic Limit.  When calibrated against a weaker walled shell with a cavity for HE the shell quality would have to be lower.  Thus the ballistic limit is again lowered. The formula does not include nose break or shell shatter.  That would have to be determined on a case by case basis.

The effetto-pronto (E.P.) weren't considered HEAT shells by the Italians though they had similar construction.  They seemed to produce a slug that affected the armor like a HESH war-head rather than HEAT shell.  This may be considered an explosive formed penetrator.  Though this 'penetrator' acted more like the bullet of the Polish wz. 35 AT rifle than a modern EFP.  The penetration number is not necessarily a complete penetration but a thickness where behind armor effects are obtained.  In fact it was a broken HEAT shell which had good results.   Once the slow acting base fuse was replaced with a German style fast acting nose fuse the E.P.S. worked as a proper HEAT shell.

WW II Ballistics Tank Gun Penetration - Poland

Armor Basis is Averaged and Normalized to RHA BHN 270
Penetration figures use 50% success criteria.
Gun TypeAmmunitionAngleMuzzle velocity Penetration (mm)
100 m300 m500 m1000 m1500 m2000 m2500 m3000 m
20mm Nkm wz 38AP 856 m/s (2808 ft/s) 36 30 24 12
37mm/L45 wz. 36APHE 823 m/s (2700 ft/s) 61 53 47 32 21
47mm/L18 Vickers QFAPHE 488 m/s (1601 ft/s) 37 32 28 21 19 17
47mm wz. 25APHE 400 m/s (1312 ft/s) 37 32 29 24 21 19
75mm/L30 wz. 1902/266.4 kg. APHE 550 m/s (1804 ft/s) 76 72 67 57 48 40
75mm/L30 wz. 1902/266.1 kg. APC 570 m/s (1870 ft/s) 73 67 62 49 39 34

Early war AP caps seem to be of poor design.  Some like the French were quite thin and may not have worked very well.  Others were rather large and elongated to help ballistics.  They may have broken off when encountering highly sloped armor plate though most tanks of the time had vertical armor.  Still others like the US 37mm M59 and German 50mm Pzgr. 39 while aiding penetration may have hindered ballistics.