Even if you apply just a little bit? What if I just re-apply lube once the feeding starts taking a turn for the worst?

Umm.. you may want to edit that seeing as how the non verified members have been restricted from the "buy or sell parts/accessories" section.

At least they're metal.

I own both KA and MAG brand mags. They both work great in my JG416. They feed wonderfully although the KA ones are a bit of a tighter fit. However, in my ICS M4A1, they both need to be shimmed or held to feed properly. It's just the ICS mag well is so big there's a lot of room for them to wobble. Once shimmed they're both great again.