France.[1] According to the French Field Artillery Regulations (footnote to par. 277), a gun firing time shrapnel covers effectively a front of 25 m., and a battery of four pieces, a front of 100 m. This intensity of fire, which is obtained when each piece fires one shot with proper corrector and range settings (the battery four shots) Aubrat calls "Density 4." When rafale fire (two shots per piece) is employed against a front of 100 m., with proper corrector setting, density 8 is obtained. When the front exceeds 100 m., the deflection of the pieces must be changed between successive shots (tir avec fauchage). To obtain density 8 against a front of 150 m., each piece must fire three shots, as prescribed in the regulations. When progressive fire (tir progressif) is employed, four different ranges are given, of which only one can be considered effective. When not sweeping, in this fire, each piece fires two shots, thus also obtaining a density of 8. A density of 1 always corresponds, therefore, to one round, fired, with proper corrector and range settings, against a front of 100 m. When a battery (four pieces) fires one salvo against a target having a front of 50 m., density 8 is obtained; by firing two salvos, density 16 is obtained.
The Commission d'études pratiques du tir has made a thorough investigation into the effect produced by shrapnel fire. The following table gives a general idea of the effect to be expected when firing against service targets (i.e., the percentage of figures one may expect to hit when employing fire of varying density):
- ↑ The following is taken from Lieutenant-General Rohne's essay on the work of Squadron Commander Aubrat, Les exercices de service en campagne. The essay mentioned appeared in the December, 1907, number of Artilleristische Monatsschriften.
