The Remington 870 Express contains a polymer trigger group assembly that most gun owners are familiar with. However, the look and feel of this trigger group could be a whole lot better. Not only that, but a polymer trigger group is believed to be less durable. That is why more Remington 870 shotgun owners are upgrading their existing shotguns with a police metal trigger group assembly instead. This particular metal trigger group is the same one that you’d find in a real Remington 870 Police shotgun. What is so great about this trigger group assembly is that it’s made out of metal, which means it is more durable and more reliable than the OEM polymer trigger group that comes with the Remington 870 Express. It also has a much better look and feel as well. Some people think that it’s made of steel but it is made of aluminum.