[Stewart]

The example is the Hispano Suiza 20mm cannon, widely used in fighter aircraft in WW2. The cartridge is 110mm long, rimless. A HE (High Explosive) projectile weighs 130 grams, and carries 6 grams of TNT. A solid non-explosive projectile weighs 150 grams. Both are fired at a muzzle velocity of 850 m/s.( Should be 840M/S!) TNT has a detonation speed of 7.000 m/s.

Kinetic energy (Joules) = 0,5 x projectile weight (kg) x the square of the muzzle velocity (m/s)

The muzzle energy of the non-explosive round is calculated as follows:
0,5 x 0,150 x 850 x 850 = 54.188 Joules, or 54 kiloJoulesShould be = 52.92Kj.

The muzzle energy of an exploding round is calculated as follows:
0,5 x 0,124 x 7.000 x 7.000 = 3.038 kJ Should be = 840X840X130/2000 = 45.864Kj. Then the explosive content should be found by multipliing the energy yeald per gram, times the number of grams. The yeald of Grade one TNT is 4,185J/Gram or 25.11Kj for a total of 70.974 Kj or on the surface appierance 34.1% increase in energy effectivness! But this is false. The solid AP projectiles will drill right threw the target plane and unless it hits some very strong massive part will waist most of their energy on the air on the far side of the target.

This is important now, but not back in WW-II because the planes of that time had numerious single point failures which would down the plane and were vulnerable to plain bullets. Then the effect of bursting munitions is widely over stated as it relates to WW-II planes!

To this should be added the kinetic energy of the round directly prior to explosion:
0,5 x 0,130 x 850 x 850 = 47 kJ
Total = 3.085 kJ

Meaning that the explosive round has 3.085/54 = 57 times the energy of the non-explosive round.Massive failure of the math proccesses!