To reliably hit the heart with a knife you need to sink the blade 3.5 - 4.5 inches beneath the skin.
When you are in full Battle Rattle, with plate carrier or tactical vest, and mag pouches across your chest, how many inches does your blade need to reach just to hit skin?
Add those two numbers together. Add another inch or 2 to allow for attacks that come in at an angle.
Now: How long is the blade of your fighting knife?
Is it long enough to reliably push past magazines and vest, then plunge 3.5 - 4.5 inches beneath the skin to reach the heart? Once your blade is immersed in the enemy, do you have serrations to help cut heavy webbing and vest material when you twist?
Do you need a new fighting knife with a longer blade?
If your go-to fighter is not at least 7 inches, you should probably leave it off the battlefield.
Kerodin
III
