1. Ensure your pistol is legal to re-import (366-499fps) back into the country
2. Ensure your pistol has a unique serial number, if not get it engraved
3. Go to a customs office, they will fill out a Y-38 form (this is what you need the serial number for)
4. Prepare your pistol to comply with the airsoft laws in the state you will be visiting (orange tip)
6. Return to Canada, declare airsoft pistol and produce Y-38 to show you bought it in Canada and it's all on the up-and-up.