Bullet Penetration Chart

[denton]

Fabs, I did major in physics, but it was a LONG time ago, and I haven't had much reason to apply the math of stable and unstable equilibrium since then.

Yes, the fundamental idea is that the dimensions, and rotation speed, were deliberately chosen so the 223 military round would tumble on entry. Exactly how they did that... I don't know. I do know that the Warsaw Pact absolutely howled over it, saying it was unfair, etc. Then they developed their own version of it, and the howling stopped.

Of course, for hunting, most of us want something a little more stable, so the bullet will push the mushroon through the wound channel. That is even more destructive.