Test Report No 2
The penetration of 230gr 45 ACP, 125gr 9mm, 158gr 9mm bullets
into sand.
R. S. Taylor, S. Bryce, D. Cassidy, D. Reece, Aintree Shooting Services Ltd, Liverpool.
Abstract :
The penetration of 230gr 45 ACP, 125gr 9mm, 158gr 9mm bullets
in sand is measured and a relationship sought between penetration
and velocity.
Introduction :
While the tests described in Test Report No 1 provided useful
pragmatic design information, it was concluded that too many different
bullet types had been used to enable any fundamental relationship
between bullet penetration and velocity to be determined. In this
test a single bullet type was used and fired at a wide range of
velocities.
Apparatus and experimental method :
As described in Test Report No 1.
Details of cartridge loads and the firearms used are given in
Appendix C.
Results :
Data is given in Appendix B.
Graphs of penetrations and distances travelled are given in Appendix A, together with a graph showing
the percentage of bullets passing each value of z. (Data from Test Report 1 is also shown on this graph
for comparison)
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45 ACP 230 gr |
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9mm 125 gr |
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9mm 158 gr |
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For each calibre, the penetration (z) appears to be substantially
independent of velocity until damage occurs.
There is an approximately linear increase in distance travelled
with velocity though this tends to level out at around mach 1.
In the case of the 9mm rounds, damage occurred at about 1500 -
1600 ft/sec and both penetration and distance travelled fell off
sharply, presumably due to the effects of mushrooming.
The slower, heavier 45 bullets remained undamaged and for each
velocity showed higher penetration and distance travelled than
either of the 9mm.
The different weights of the two 9mm bullets appears not to affect
either penetration or distance travelled, though the lighter bullet
suffered greater damage at higher velocities.
Conclusions :
So far, it has not been possible to derive predictive parameters
from the data. The apparent independence of penetration
and velocity remains counter-intuitive but confirms the results
described in Test Report 1 and provides a further pragmatic measure
of the effectiveness of comparatively small thicknesses of sand
in stopping bullets over a wide range of velocities and energies.