I've got a few D&H mags with Magpul followers, very good mags. Got them from Saskatoon Gunworks.
ASC 10/30 LAR-15 pistol mags.
The early LAR mags were terrible. I picked up the c-products version with the upgraded feeder and spring (orange version) and they feed very well I’ve found.
That's what I noticed with the two LAR mags I tried. One would not even eject...
How about the Norinco 5.56 metal mags? They seem to be the cheapest currently for sale.
Where can one find these??
I've got several of the black aluminum ones with orange followers. If I put a full 10rounds, the first one more often than not fails to feed. For the most part, mine are functionally 8 or 9 rounders.
I have 4 Cross-Mags (so far) and haven't had anything but perfect reliability so far for the last 1.5 years
EDIT to add: In a Kel-Tec RDB