Pinning the mags is easy and reallly kind of a joke as far as gun control is concerned as you can just pull the pin out and fully load the mag. Be warned though that getting caught with a fullly operational high cap has a stiff mandatory sentence (last I heard 9 years in prison).
AR stuff is hard to come by in the US these days, never mind trying to import it. For better luck you might try here:
At the very least you might pick some up on the dealer forums or the equipment exchange if you pay attention.
dbm: Here is a quick HOWTO for pinning magazines that I found a few months ago.
Originally Posted by JRT6
I agree that requiring high capacity magazines to be pinned is not a viable means of gun control, but I'm glad it's legal because it would save me from having to buy new magazines (I have a single stack 1911, so that I don't need to modify anything to be legal in Canada).
+2 on http://www.canadiangunnutz.com/
Look in the EE, also, Wolverine Supplies in MB usually has some.
For the record, all mags must be pinned to 5, and that disassembled mag comment is way off: unpinned mag = mandatory minimum of 5 years at camp fed (minus time served before sentencing x2, good behavior, and boy scout badges earned while inside) but you will get a prohibition order which means you cannot own firearms.