Looking for velcro backed magazine carrier suggestions.

On my first trip to the range with the XCR, I had to show it off to the kids working the counter. One commented "When you decide to put on an optic, you will want to flip the rifle around in the case, so that the optic is not toward the ground, so that it does not hit the ground if the case is dropped."

So, I finally bought and attached a Primary Arms SLX, flipped the rifle around, and the original metal 30 round mag wants more space than is available between the rifle and the bottom of the case. I'm thinking that it might be better to store the rifle in the case with a 10 round magazine in place, to keep debris out, and figure out a way to velcro the metal magazine to the inside of the case (since I filled the four pouches on the front of the case with pmags).

I'm thinking cloth, with either a good hold or a flap to hold the magazine in. Can't have the sticky velcro on the front or it will stick to the other side of the case.