On 15 August 1902 in Kaiser Wilhelm’s
presence Krupp carried out some experiments to check the resistence of 3 mm hard steel plates
against shrapnel filled with steel bullets, weighting 10 g. A 75mm L/30 Krupp
field gun with a muzzle velocity of 500 m/s fired at 3500 m against a field
battery in French formation, i.e. with the wagon body up-ended alongside the
The gun fired
20 rounds. The range of shots was from 30 m to 130 m, 65 m on an average. The gun shield was hit by
80 bullets: 63 splinters (79%) pierced it right through. Among the 16 men (8
standing and 8 sitting) depicted behind the shells, 13 were hit by around 62
bullets (81 %).
wagon shield, which was reinforced by the wooden wall of the wagon itself,
was hit by 76 bullets: only 13 splinters (17%) pierced it right through.
Among the 12 kneeling men depicted behind the shells, 9 were hit by around 14
bullets (75 %).
was carried out against the carriage N° 4, this time without crew behind. The
gun fired 11 more rounds to it. The range of shots was from 20 m to 110 m, 60 m on an average. The gun
shield was hit by 55 bullets: 30 splinters (55%) pierced it right through.
another shield was fired at 2000
m with shrapnel filled with hard lead bullets. This
time no splinter pierced the shield.
On the other
hand Rheinmethall later found that a 4 mm shield kept out the steel bullets even
at short ranges. Therefore the German Army kept a 4 mm shield for its field
guns, even if France
had adopted a 5 mm
shield, followed by most of the European armies that choose a thickness of 4 mm. Also for their horse
artillery, where the reduction of the weight of the gun was essential, both France and Russia preferred a stronger 3.5mm
consequence of these experiments, Krupp came to the conclusion that the
adoption of steel bullets would be
favourable when one’s opponent were known to be equipped with gun shield of
less than 4 mm
thickness. However the use of steel bullets entailed a loss of efficiency
against infantry, since the steel bullets, being less dense than the ordinary
mixed metal bullets in the proportion of 8 to 9, did not carry so far and
were less effective against troops in the open.
larger size of the steel bullets sensibly reduced the number that could be
packed in a shell. Actually Krupp found that its field shrapnel, which
normally held 300 mixed metal bullets of 11 g, would only hold 265 steel bullets of 10 g.