Tight fit for 30 rnd mags. - Shellback Tactical Triple Stacker Open Top M4 Mag Pouch

It's a bit of a struggle (tight fit) loading mags into the carrier. However, once in, there's absolutely no rattling. I suggest a dump pouch for empty mags on the go. 20 rnd mags fit in the front row but a bit deep for the back row. The 6 molle straps hold the carrier very firmly. This is my first time I used a thigh rig, and it's perfect. I loved getting it off my vest, plus reloading is a couple of seconds faster. As for the snug fit, I have a feeling that after break-in, it will loosen up a bit.