Think about how fast the average bullet is sent down a hole that is to small for it (the barrel) and then meets MASSIVE air resistance as it travels at extremely high speed through the atmosphere. Bullets are simply HOT. Ask anyone who has been shot! I have an uncle who took a .357 at point blank in the gut. [:'(]He said all he really remembered was a loud bang and then a burning feeling in his stomach.

I can only assume the "black ring" you are talking about is actually cinged paper? If you shoot a can of gasoline or propane it EXPLODES on impact. Think of the bullet as a 3K fps match.
RA