Some Airsofters make the horrible mistake of buying the 0.20g BBs from a Walmart or Canadian tire for their high quality gun. Constant use of these low quality BBs will end up killing your gearbox.
When playing most Ottawa airsoft fields, you may notice that the fields are forest based. So choosing a appropriate camo for the field your playing on is important.
Although AirsoftGI is out of the US, they have created an excellent infographic on Canadian Airsoft Laws and Regulations updated for 2013.