This was posted at the bottom of Trailrider121's 1st post about this.I called CCI this morning to verify it and they told me it was not true.They are made with different heat specifications.
NOTE 1: According to Speer/CCI Technical Services - Both the CCI 550 Small Pistol Magnum and CCI 400 Small Rifle primers are identical in size. Both primers use the same cup metal and share the same cup thickness. Both primers use the same primer compound formula and same amount of primer compound. They can be used interchangeably.
That is very useful information for me! Thanks for sharing!
