Gun show tables and the occasional indian reserve gun shop. And every now and then, in the possession of some ignorant that did not have a clue how miserable he could be if caught at the border exporting ammo from the US.
It's been a while since I bought ammo in the States but you used to be able to bring back up to 5K. I guess this has all changed? If so is it our end or their end? TC
Theirs. Homeland Security and Anti-terrorist measures limiting the export of ammunition and military goods by people not registered to do so (which requires citizenship in the US), and, among other things, the exporter,which is what a guy that buys ammo *if he could find it* in the US and takes it OUT of the US of A, is, must be registered and paid up for their licenses, and the maker of the product has to be registered and paid up.
Royal, expensive PITA, when the small makers can sell all the custom gun parts they can make in their own back yard, as can the ammo maker these days.
Canadian law may well allow you to bring it in, but to get it out of the states, requires some work to do legally.
There is some info in the stickies at the top of the forum index.
http://www.canadiangunnutz.com/forum/showthread.php/71789-How-to-Import-Ammo-from-the-US-(Legally)
Cheers
Trev