Heavy duty pouches hold double stacks well - 5.11 Double Pistol Mag Pouch 58712

Bought two for use in competitive shooting. They are heavy duty ballistic nylon with strong elastic to hold the magazines. Will hold 40 S&W extended double stack mags very securely even with the Velcro straps in the pockets. The snap belt loops are a little hard to position, so don't count on repositioning it on the fly.

If using it in a tactical situation, I would recommend playing with it to find the best position, as well as trying to tear it off to determine if it needs stronger fasteners.
Pros: Holds Extended Mags
Cons: Time Consuming to Adjust or Reposition

This review was written in the old system and had content requirements that are different than reviews written today.