And the other concern is whether the CBSA will drop the dime to their US counterparts. I had this happen a few years ago while legally exporting some blank ammo for a movie we were working on. I was asked anything to declare? Answered "yes" 30000 round of blank ammo, the CBSA broad said wait a minute, closed her window and picked up the phone. 2 minutes later I was surrounded by US Border Protection agents, guns drawn.
Fortunately the lead US agent realized I had spoken with him just minutes prior, he checked my paperwork again and all went well, however.........
OP Most scopes are covered by ITAR, so best to shop at home.