Interpretation of Russian Penetration Curves

[rexford]

ANALYSIS OF RUSSIAN PENETRATION CURVES

The Russian Battlefield web site provides penetration curves for Russian and Lend Lease tank guns in use during WW II, where the graph is available at http://www.battlefield.ru/library/archives/weapons/pics/penetration.gif. The following discussion attempts to fill in the missing information regarding armor type and success criteria, and provides some cautions on the use of the curves.

1. The plots for 57mm thru 122mm guns are straight lines, whereas the data should present a curve

2. Comparison of the Russian penetration data for 75mm M72 (M4A2) and 6 pdr (Mark IV) guns with Allied figures suggests that the armor type is homogeneous, the Russians are using the Initial Penetration criteria (20% of hits succeed) and one data point at 500m has been extended to other ranges using a straight line approach

3. The curves for Allied 40mm and 37mm penetration show extreme fall-off with range and are questionable due to zero slope at 1150m (no change in penetration with range)

4. The Russian 20% IP criteria can be converted to 50% success using a 0.9443 multiplier

Applying expected penetration-vs-velocity-vs-range profiles for stated or likely ammunition types with the above assumptions results in the following revised penetration figures for Russian use tank guns (homogeneous armor, 50% of hits succeed):

1. 6 pdr (APC): 102mm at 100m, 85m at 500m, 68mm at 1000m

2. 76.2mm F-34 (APBC): 78mm at 100m, 69mm at 500m, 59mm at 1000m

3. M4A2 75mm (M72 AP): 108mm at 100m, 92mm at 500m, 76mm at 1000m

4. 122mm (APBC): 207mm at 100m, 189mm at 500m, 167mm at 1000m

5. 85mm (APBC): 136mm at 100m, 120mm at 500m, 102mm at 1000m

The above estimates are consistent with Russian firing tests against the 80mm design spec side armor on Tiger tanks during April and September 1943, where the 6 pdr tank gun had a 600m penetration range and APBC fired by the 76.2mm T34 gun failed to defeat the Tiger side armor at 100m and 200m range on perpendicular hits.

Analysis of 20 firing test results against the 80mm design thickness side plates on Tiger suggest that the average plate resisted penetration like 84.5mm of good quality armor (increased resistance due to combination of thicknesses above 80mm and improved ballistic response) .

[Keke]

Thanks Lorrin. Link ain't working btw.