I believe Brownells has the new USGI contract for magazines.
But PMags are the answer. If you have to go USGI, Colt, Okay Industries, and a few others are known and trusted.
"And Shepherds we shall be. For thee, my Lord for thee. Power hath descended forth from thy hand, that our feet may swiftly carry out thy command. So we shall flow a river forth to thee and teeming with souls shall it ever be. In nomine Patris, et fili, et Spiritus Sancti. Amen."