I'm not trying to justify what gun manufactures are using in the construction of their guns, but with the advancement made in aluminum alloys and coatings today, if the right materials are used you can have an extreamly durable & light gun made. We've seen aluminum alloyed to the point that it couldn' be machined with conventional tooling. With squeeze casting the the material is more dense than steel. Hardcoat anodizing is better that a blued steel in a duck hunting environment (rainy weather).