Effects of Eccentricity of Boattail and Mass in 155mm Howitzer H.E. Shell MK 1

The effects upon range, deflection and dispersion resulting from abnormal dimensions or mass distribution in shell must be kept small if accuracy of fire is to be ensured. The action of general abnormalities of shell is traced through four different regimes of the flight. Measurements of four particular abnormalities of shell are discussed to some extent. Theoretical effects are computed for some abnormalities of shell and estimated for others. Experimental determination of corresponding effects is undertaken from two samples of abnormal shell. These results are compared with similar experimental determinations made by R. H. Kent for 155mm Gun H.E. Shell Mk.III. The methods suggested in this report should have application to the determination of allowable manufacturing tolerances for shell.