Loose the 30rd make and use a 10rd, or even a 5
5 & 10 round magazines are the same size. One is pinned.
I have 10 round mags for both ar15 and 10.
There smaller,and when I carry with a normal rifle sling I don't have a mag stabing me in the back.
I don't need more than ten rounds ,extra weight.
I bought mine years ago ,way before this stupid new law.