[Turbopilot]

The penetration comes from the density of the projectile. This is true regardless of whether the object being penetrated is steel plate or fiber-based body armor. A bullet made of those heavy metals without Teflon would penetrate as well or even better, but would wear out barrels too fast.

If I was too harsh in my original post I apologize. The “Teflon cop-killer bullet” myth, like the “plastic gun that’s invisible to X-ray machines”, was a myth that the media invented to lie about guns and I hate seeing it spread.

[PowderMonkey]

"If I was too harsh in my original post I apologize."

You are a class act, Turbopilot. We could use more of that around here.

[mountainlion]

I have Teflon treated levers barrels of my guns. It used to be the real hot thing but now there are a log of detractors. It is supposed to reduce friction and barrel fouling. If I remember correctly bullet energy is mass times the velocity squared. Penetration is a whole different science that goes into depleted uranium, lead... and what is being penetrated. There are some pressed powder bullets like the Varmint grenade and military penetrator/expanding one they showed on the Military Channel. There is a lot of truth, hype and lies out there and sometimes it is hard to tell the difference.