QUOTE(Snake-eater 1 @ Nov 21 2007, 08:24 PM)

ESP and CDP allow replacement of barrels of original configuration and there is no exclusion of other calibers. (pages 20-24 of the 2005 rulebook)
This is only PARTIALLY correct.
Page 22 of the IDPA Rulebook-----
4. Custom Defensive Pistol Division (CDP)
Handguns permitted for use in this division must:
1. Be semi-automatic
2. Be .45 ACP caliber.
etc, etc, etc
So, there IS an exclusion of other calibers for CDP. You can't swap in a .400 Corbon or a .45 GAP barrel in a 1911 and use it for CDP. Any replacement barrel for your glock that isn't available in a caliber available in the original factory model moves you to ESP.