Actually, I don't think any variant of the Galil ACE uses a newly-developed (i.e. proprietary) magazine, which was a smart if obvious choice on IWI's part. The ACE Ns use STANAG 4179s, the other 5.56s use magazines from the regular Galil, 7.62x39s use AK mags, and 7.62x51s use magazines from the Galil 7.62.
