CMI suppiled some pretty lousy M9 mags to the military; hope they do a better job w your mags.
Lost their military contract BTW. New M9 mag contract went to Airtonic for up to 14 _million_ more M9 mags!
My best results w Berettas have been w PB (Pietro Beretta) , MG (MecGar), and MDS (Meccanica del Sarca) mags.
The "company line" from Beretta is to only use Beretta, MecGar, and MDS mags anything else isn't "up to standards".
The CX4 carbines are designed with inserts for the 90 series (92,96, 90-2), PX4, and 8000 (Cougar) pistol mags depending on caliber. A few of the guys I have talked with were talking about having thier departments order CXs to replace shotguns in certain applications so they could keep the gear load down but round count up. They already had 92s with four mags on the belt to start with.