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)

 

min veloc

max veloc

min z (in)

max z (in)

average z

average deviation

standard deviation
45 ACP 230 gr

 547

1198

12.15

20.00

15.88

1.36

1.69
9mm 125 gr 

 312

2050

8.13

15.38

12.30

1.56

1.87
9mm 158 gr

476

1730

8.13

15.75

12.14

1.29

1.57

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.


APPENDIX A



APPENDIX B


APPENDIX C