A leather(or otherwise flexible) 1911 .45 mag holder will work. If it`s your one and only for the .45 it will stretch it just slightly. I like Falco holsters and acc. Just contacted them the other day and they don`t have holsters for the Shield yet but they sell several types of clip on mag holders. Their base rough side out with clip mag holder is $12 if I recall. I have one for my M&P and it works well. I think(gulp) the one they have for the .45 single stack will serve you well. Good Luck, John