If I had a double rifle and was considering a reflex site and mounting it, it would be either a Docter, a Docter clone or a Trijicon RMR. These are very small units, under 2 oz., but tough and reliable. With the Docter and its clones, the Burris Fast Fire 336 mount is a flush mount and the above sights screw directly to it making it low profile and without bulky Picatinny base and it dispenses with clamping. The Burris Fast Fire red dot is considerably less expensive than the Docter. Burris's customer service is unparalleled. Unlike the Docter and clones, the RMR depends on a Tritium lamp and fiber optics for illumination dispensing with batteries. The Docter and Fast Fire series have long lasting batteries and are reported to be good for 50,000 hours of continuous use. I am aware of some that have used the 336 mount and Fast Fire on double shot guns for turkeys where the payload is extremely tight and the shooter's eyes have trouble with conventional sights. I have been using reflex sites for about 20 years because of difficulties with blade, leaf and target acquisition. I have progressed from the bulkier to the smaller sights and am pleased with their performance on single barreled pumps, autos and break open single shots used for wild turkeys.
