https://canadianfirearmsblog.ca/itar-and-canada/
Many people do it but it is a violation of International Traffic in Arms Regulations of the United States.
You can use the services of licensed exporter the cheapest legal way would be to just order it from brownells it is under the 500 USD exemption to Canada so you just pay for shipping no additional fees.
Or you could try to drive the parts across the border yourself in violation of ITAR
Criminal penalties include a fine of up to $1 million and/or up to 10 years in prison for each violation. Civil penalties include a fine of up to $500,000 for each violation. Other penalties for violations of the ITAR include: The denial of export privileges and/or.