Descriptive statistics for measured back face signature (BFS) (mm) due to the two bullet types shot at different angles into two types of armour
| Impact angle | BFS (mm) | |||||||
|---|---|---|---|---|---|---|---|---|
| HG1/A+KR1 | HG1+KR1 | |||||||
| HP bullets | FMJ bullets | HP bullets | FMJ bullets | |||||
| Mean | SD | Mean | SD | Mean | SD | Mean | SD | |
| 0° | 30.0 (5) | 3.5 | 33.6 (5) | 5.2 | 13.4 (5) | 0.9 | 13.8 (5) | 2.1 |
| 15° | 27.6 (5) | 2.1 | 32.0 (5) | 3.0 | 10.6 (5) | 2.2 | 15.8 (5) | 2.2 |
| 30° | 24.2 (5) | 2.2 | 27.6 (5) | 2.6 | 9.6 (5) | 1.7 | NR | NR |
| 45° | 21.8 (5) | 3.7 | 21.8 (5) | 1.3 | 8.5 (4) | 2.1 | 8.8 (4) | 2.5 |
| 60° | 17.6 (5) | 2.6 | NR | NR | 3.3 (3) | 1.5 | NR | NR |
| 70° | 13.0 (3) | 1.7 | 14.0 (3) | 1.0 | NR | NR | NR | NR |
| 75° | NR | NR | NR | NR | NR | NR | NR | NR |
| 80° | 4.3 (3) | 4.0 | NR | NR | NR | NR | NR | NR |
Number of data points in brackets after mean value; n<5 due to bullet exiting the side of the armour panel. NR (no result) indicates no BFS recorded due to bullet exiting the side of the armour panel.
FMJ, full metal jacket; HP, hollow point.