Yea that is what I was looking at, some cheaper than HK basic mags. Have to say though the one in the gun at my local store felt like I could bend it in half with my bare hands (IT wasn't the FN mag, probably a standard GI mag).
I have several I have tried with my FS2000, with 100% guaranteed failures to extract/feed on every round. And, no, I didn't fill them up with 20 rounds (some say loading 20-rounds in these mags will cause some AR15s to jam). It's okay with me, because the 20-rounders are a bit short and thus tougher to remove.
I have heard from others that the curved 20-rounders will work, if you really want a 20-rounder.
Yeah, I didn't try all my 20-rounders out, but I tried 3, and each of them had the exact same jam on every round in the mag. I figured it was a design thing, but if your 20s are working, maybe it's just me!
It could also be something with my particular rifle. I have read some postings from others on the net and it appears some people have feeding problems with the 20s like me.
I have read that the curved 20s work well pretty universally, though.
I think most of the quality GI mags will be fine. I think the MagPul followers are the best improvement one can make for an AR mag. For those who want the "REAL" factory correct mag that the F2000 was originally designed to use, CMMG has some Belgian Mfg. FNC mags.
They're even more spendy than the HK mags though. The FNC mags have steel bodies so they do hold up very well. I suspect most won't consider them as their first choice, but if you're an FN purist, these are the factory correct mag.