So, yes, a Bulgarian company called NI-KO makes polymer magazines for the M16 FOW, and have for at least two years now.
The man who designed them, Ivan Kolev, is a former employee of Arsenal Bulgaria and designed the polymer “waffle” pattern 7.62x39mm and 5.56x45mm magazines for the Kalashnikov, which are some of the best in the world.
I had my first limited exposure to them in Feb. of 2010, when the moderators, staff, and industry professionals of M4C attended a special class at US Training Center taught by Ken Hackathorn and Larry Vickers.
Ken had a 40 rd. magazine that he was trying out, and it performed well for the class.
Tad Tae getting some trigger time using Ken’s training carbine.

I was contacted about doing a T&E by an affilate of Elk River Tool and Die, who will be importing both firearms and accessories from Bulgaria.
He advised me that the first generation 40 rounders ran fine, but that over time they did develop some issues with the feed lips, which have apparently been corrected in this current generation that they are importing.
I received two of the 30 rd. magazines today. I loaded one up with thirty rounds of M855 with no issues, and it seated in my Noveske Mk.18 as easily as when seating the magazine with 28 rds, which is to say very easily. The magazines dropped free both loaded and unloaded, bolt locked back or forward.
I lost the light before I could disassemble one of the magazines to look at the guts, but I will do so and take pictures as soon as possible.
The magazines look to be well made, but not quite as polished as a current generation Magpul Pmag. They do fit just fine in a FN FNC, and I will try them in a post '86 dealer sample H&K 416D.
I will use these magazines hard and see how they perform, and report back as I do.
I have no idea what the price point per unit will be, but Elk River will be importing both 30 and 40 round new generation magazines.
Here are some pictures I took right out of the box.













