They look like sketchy junk to me. A guy on the dealer thread about them said the holes where they drilled them out aren't even deburred and are quite sharp.
More importantly, possessing remanufactured .223 mags with a little ".50 Beowulf" stamp on them is in a legal grey zone at best. These make the PCV mags look good in comparison... and that's saying something.
Think about it, who makes aluminum USGI mags in Canada? Nobody.
In order for them to be "made in Canada" someone imported them as .223 mags, drilled out the welds and rivet (illegal), fiddled around with them (why?), and then slapped them back together (poorly) to market them as ".50 Beowulf" mags.
I'm sticking to the C-Products and AA mags.