Just picked some of these up from a Vancouver gun shop. I'm not sure what brand they are, but if I would guess I would say KCI. The first time I went to use them, they wouldn't fit in my magwell without a good "rapp" on the bottom while I twisted them in. Also, from the pics you'll see some big discrepancy from the original Norinco mags that came with my rifle.
Exhibit A: Bad Mag on left and Norinco on right
You can see that the feed lips on the bad mag are much further ahead. They are also not straight. You can see how they go off at an outwards angle compared to the straight Norinco lips. My Norinco M305 was not able to pick up a single round from these mags without jamming.

Exhibit B: Bad Mag on left, Norinco on right.
The KCI has a much fatter front (hard to see), but this makes it hard to put into the mag well

Exhibit C: Bad Mag on top, Norinco on bottom
Easier to see the fat front. Also notice the feed lips

Exhibit D:
These mags are not internally limited and don't use a rivit. Instead they use this notch. I don't mind it except they are notched too high and make it really hard to put the mag in on a closed bolt. The Norincos have extra room which is nice.

Anyone know where I can get some good ones
Exhibit A: Bad Mag on left and Norinco on right
You can see that the feed lips on the bad mag are much further ahead. They are also not straight. You can see how they go off at an outwards angle compared to the straight Norinco lips. My Norinco M305 was not able to pick up a single round from these mags without jamming.

Exhibit B: Bad Mag on left, Norinco on right.
The KCI has a much fatter front (hard to see), but this makes it hard to put into the mag well

Exhibit C: Bad Mag on top, Norinco on bottom
Easier to see the fat front. Also notice the feed lips

Exhibit D:
These mags are not internally limited and don't use a rivit. Instead they use this notch. I don't mind it except they are notched too high and make it really hard to put the mag in on a closed bolt. The Norincos have extra room which is nice.

Anyone know where I can get some good ones