Hypothesis
It takes 27J to break the egg in the 5 cm block and 101 J to break the egg in the 10 cm block. Based on the data in Table 13, using the dissipated energies, the 95 grain .380 bullet should allow enough energy through at 8 and 12 layers to cause the egg to break in the 5 cm block but dissipate enough energy to not break the egg in the 10 cm block.
Results
My father fired 95 grain .380 bullets from a pistol at our ballistics gel rig with the egg embedded inside. The distance from the pistol to the rig was 10 feet. Kevlar sheets clipped together were placed in front of the gel block as in the slingshot tests.
The first shot at the 5 cm block with 12 layers of Kevlar was low and did not break the egg, but the second shot was centered over the egg and broke it.
Figure 14. .380 bullet after impact with 8 layers of Kevlar.
Using the energy dissipation fraction for 12 Kevlar layers I found in the slingshot tests (See Table 8) this confirms my prediction, as nearly 43J of the bullets energy made it through the Kevlar and hit the gel, enough to break the egg at 5 cm.
Table 15. .380 Test of Kevlar dissipation with 5 cm block.
The first shot at the 10 cm block with 8 layers of Kevlar was centered over the egg but did not break it. This too was expected since only 56 of the 101 joules necessary to break the egg passed through the Kevlar. The bullet also did not penetrate the Kevlar, confirming that 8 layers will stop a .380.
Table 16. .380 Test of Kevlar dissipation with 10 cm block.
We also tested the hypothesis that 7 layers of Kevlar were needed to keep the bullet from penetrating by firing at 6 layers of Kevlar with a hollow-point bullet. The hollow-point bullet did penetrate the 6 layers of Kevlar but it went under the egg, so it was not broken.
Figure 15. Impact craters on outer layer (left) and inner layers (right) of Kevlar.
Figure 16. Path of .380 hollow-point bullet through ballistics gel.
Figure 17. The .380 hollow-point bullet plugged with Kevlar (right) did not mushroom as much as the .95 grain .380 bullet.
Conclusion
My hypothesis was proven correct which validates my results for how much Kevlar dissipates energy.