Okay..... I don't know why people continue to say that there are only two sources of FN P90 magazines..... There isn't. THERE ARE THREE!
FNH USA
1) The FNH USA Magazines come in either 10rd, 30rd, or 50rd. In the end they're all the same magazines. They just have the stupid plastic block on the magazine floor plate. Take a Dremel Tool and file and cut it off the floor plate. Boom.... 50rd magazine. Same springs, same followers, etc. They are not made any differently. As for why FNH USA ships the PS90 with a 30rd magazine is beyond me. 10rd I understand for Ban States, but 30rd for Free States? Not a clue unless some state somewhere has a law that restricts you to 30rd magazines.
As for quality and feeding. 100% kick ass. No issues what so ever.
AR 57
2) AR57 magazines - AWESOME! They're not made in Korea, they're made in the USA. They are 100% a perfect clone of the FNH USA 50rd Magazine. If it wasn't for the small AR57 logo on the magazine I'd have no clue that they were AR57 made. Same length spring as the FNH USA, same quality plastic, etc..... Not a single feed issue. I have two FNH USA Converted 30rd Magazines and seven AR57 magazines. They all work like a charm and function perfectly. Best part is they retail for $26.00 at
www.57center.com/. Much cheaper then factory FNH USA magazines. They feed the SS97SR, the SS192 JHP, etc... No Issues. Buy them, Buy many of them and be happy.
ATI
3) ATI 50rd Magazine - CRAP. THese are the shitty made in Korea magazines that don't work worth a damn. Short springs, shitty plastic, shitty quality, shitty feeding. They also retail for $26.00 a pop but they're crap. Simple as that. Avoid them like ACORN or SEIU but give them as gifts to your enemies so their weapons suck.