Not necessarily a mag problem. However, a weak mag spring or worn follower (plastic ones) can cause the problem. I have several brands and use Metalforms in my custom guns. My wife uses Wilson 7 rounders in hers as they load a bit easier. Just a penny and a half…cobber said:help--what is the best mag for a sa ss 9mm full loaded 1911? the one with the gun will not keep the slide open on the last shot.