Here is the one I am using on my AI&P Tactical Builds now. The dual retention strips hold the shells better then the single one in the Aluminum Carriers. The one I offer here is the 6rd for the Remington Shotgun. I will have other offered soon.
Here is the info on them.
Mesa Tactical is now offering the SureShell® Shotshell Carrier made from durable, impact resistant polymer. This new polymer shotshell carrier system, available in a six shell configuration, features shell holders injection molded from glass filled polymer, secured to the receiver by a lightweight aluminum back plate with brass threaded inserts. The new SureShell Polymer Shotshell Carrier also includes an innovative dual rubber friction system that reliably holds shotshells in place. Models are available with and without integral Picatinny rails for mounting optics.
Made from injection molded-glass filled nylon
Lighter weight than aluminum
Secures to lightweight aluminum backplates by brass threaded inserts
Innovative dual rubber friction retention system reliably holds shotshells in place
Comes with/without Picatinny optics rail
Mounts via brackets attached to shotgun or via drilled and tapped receiver holes