Also make sure you declare the correct value on the customs form, insure it for that amount as well, it is up to the person recieving the goods to pay any import taxes not the sender. I sent before by fedex ground to Canada and the customs fees were charged to my fedex account, $30 fees with a $40 loan charge. So DO NOT send by fedex.
I have used USPS and UPS to send to Canada, I do not sell paintball guns through ebay to Canada, if they wanted too they could keep the gun and try to chargeback on your paypal/ebay account and both would drop your sale in a heartbeat as it broke the selling rules.
Some people are like slinkies......kinda useless but they do make me smile when pushed down the stairs.