So far, I've been through about a dozen .223 Galils (IMIs, clone builds by 3 reputable builders and even a reweld) and ALL of them worked great with both the Orilites and steel. The Orlite mags were new or like new. Steel mags were also new or like new. All the common sizes, 12s, 35s and 50s. Don't mess around with those used pieces of crap mags the kits or Century builds come with. Somewhere I have a box of them. Just too much frustration.
I have a couple UA mag adapters too.
If new mags don't work for you, your Galil is out of spec. Send the gun to TennGalil.
My preference is Orlite.
RM308