The Perazzi SR1 is available in 12 or 20 gauge. The original 2008 design. This is now the only gun in my range of guns that comes with a fairly conventional top rib that offers a sight picture that many experienced guns are familiar with. The head or sighting view of the SR1 should maintain an eye position of about 2-3m just above the rib when the gun is mounted snugly into the cheek. Looking dead flat along the top rib is in my opinion, incorrect and although it can be effective on closer range targets, it will let the shooter down on longer targets when it is important to see more of the target and exactly what you are doing. The SR1 has a very effective short ramp at the breech which also aids the target vision to some extent.
John Jeffries Custom Shotguns - Shotguns with the Best Target Vision. If you want to shoot your very best, let me take you as close as possible. The rest is up to you.