Posted this in the wrong place - but MD did see it answer - the ones he saw had a blue snap on base

FG

These are the Power Punch Bullets that Doc shows on his web site...

Is this the bullet you are talking about? I has a copper tinted gas seal - it was added to clean the barrel as it traveled up the barrel... It is not plastic and it certainly is not an elongated round ball...

Here is the web site...

http://www.whitemuzzleloading.com/images/whiterifles/white_bullets.htm