The 30 round mags fit the 92, the mag catch is in the wrong place. Machine shop or a lucky cut from a hacksaw might make it work.
You can purchase accessories directly from barettausa. They were out of 20 round mags last I looked.
Multiple Choice.......A: Glock Certified Armorer, B: NRA Certified Pistol Instructor, C: Personal Protection In The Home Instructor, D: Personal Protection Outside The Home Instructor, E: NRA Refuse To Be A Victim Instructor, F: NRA Chief Range Safety Officer, G: Nebraska Concealed Carry Instructor, H: 30 year Concealed Handgun experience, I: NRA Benefactor Life Member, J: All Of The Above