"I think a lot of your confusion here is from not having read both acts back to back. Again, the 500fps muzzle velocity figure was first set down BEFORE the Firearms Act, the only thing the Firearms Act did was to paraphrase it. C-10A came along and inserted the muzzle energy figure into the Criminal Code, along with instructions on how it applies to the Firearms Act. C-10A did not insert any muzzle energy or muzzle velocity figures into the Firearms Act, because traditionally such definitions and details fall under the Criminal Code."
I stand corrected on this.
However, the legislative history still seems to suggest that its an OR thing and not the AND, as you have suggested it means.
This is further supported by the CFC and their interpretation of the three different ways a firearm can be defined as.