5 stars because after you brace the mag on a solid surface and apply about 200 pounds of force with a sturdy mag loader you can indeed get 16 rounds into this mag.
If MecGar had made the adapter just 2 or 3 mm longer it'd made a huge difference, maybe they couldn't because of some sport rules.
It will take 16 so don't think it's defective when it seems to jam full at 14.
I'm glad I only bought one, more would be a bear to load at the range, this will therefore only be used as a nightstand mag.