Here is a link to the magazine that AIM is now carrying.  What are your thoughts on these working in a Norinco 84S?

Arsenal 20 rd 5.56 x 45 magazine

They are hard to tell because there is absolutely NO "AK 5.56 Standard" as there is for AK 7.62 & AK 5.45

You could order one and give it a try?

You might also consider buying & trying a few different mags to find what works in YOUR gun

If any mag may work best in your gun, my guess would be this.  E. German Wienger 5.56 AK mag https://www.apexgunparts.com/rifles/ak-47/ak-magazines.html

5.56 Promag for SAR-3 (5.56 AK) ProMag .223 AK mag

5.56 Promag for Saiga Conversions https://www.mississippiautoarms.com/30-round-magazine-for-saiga-223-promag-58816

Tapco 5.56 Golani mags https://gunmagwarehouse.com/tapco-magazine-galil-century-golani-sporter-223-remington-30-round-polymer-black.html

I had good luck on a Saiga conversions with Tapco PAP 85 5.56 AK mags https://www.velocityfirearms.com/product/pap-m85-30rnd-tapco-mag/

Sorry that it works out that way.  The Chinese 5.56 AK mags are nearly un-obtainium these days or priced very very expensive if you can find one...

Could also give these polish 5.56 AK mags a shot:

https://www.armsofamerica.com/ak55630rdmagazinefabrykabronimfgpolishmilitaryissueforakberyl556.aspx

The green Polish Beryl mags work in my NHM 90 (ban neutered 84S).

Fit & feed fine. Also available here.

I know firsthand that the 5.56 Bulgarian mags will nit fit in my NHM 90. I have a plentiful supply of 84S magazines. If I didn't I'd be buying more of the Polish mags. I only have 3 of them.

Bulgy circle 10s work in my 84s and NHM90, but I did have one post ban 5.56 mak that they did not work in, so I guess they are all a little different.

James