outta curiosity, how are you planning to do this?
have a sticker that has "over 400 fps and under 500fps" on the box?
CBSA is different from RCMP and CFC
they have a lot more freedoms; and you have a lot less, while dealing with em
I have seen first hand CBSA agents taking away boxloads of KJW M700's even though they had manufacturer statements listing its FPS output